View source for Census in Australia

{{Short description|National census of Australia, held every five years}}
{{About|the process and history of counting Australia's population|information on current and historical census and other data|Demographics of Australia}}
{{Use dmy dates|date=August 2016}}
{{Use Australian English|date=September 2013}}
{{Infobox census
| name = Census of Population and Housing
| logo = ABS Census Logo.svg
| image = ABS House.jpg
| image_caption = ABS House, the headquarters for the [[Australian Bureau of Statistics]]
| country = [[Australia]]
| previous_year = 2021
| previous_census = 2021 Australian census
| next_year = 2026
| population = 25,956,142
| most_populous = [[New South Wales]] (8,095,400)
| least_populous = [[Jervis Bay Territory]] (313)
| website = {{URL|census.gov.au/}}
}}
The '''Census in Australia''', officially the '''Census of Population and Housing''', is the national [[census]] in Australia that occurs every five years.<ref>{{Cite web|date=6 July 2020|title=Census Data|url=https://libguides.library.usyd.edu.au/c.php?g=508155&p=3476200|access-date=2 August 2020|website=University of Sydney|archive-date=20 September 2020|archive-url=https://web.archive.org/web/20200920115130/https://libguides.library.usyd.edu.au/c.php?g=508155&p=3476200|url-status=live}}</ref> The census collects key demographic, social and economic data from all people in Australia on census night, including overseas visitors and residents of [[States and territories of Australia#External territories|Australian external territories]], only excluding foreign diplomats.<ref>{{Cite web|date=20 July 2020|title=2021 Census overview|url=https://www.abs.gov.au/websitedbs/D3310114.nsf/Home/2021+Census+overview|access-date=2 August 2020|website=Australian Bureau of Statistics|archive-date=31 July 2020|archive-url=https://web.archive.org/web/20200731182046/https://www.abs.gov.au/websitedbs/D3310114.nsf/Home/2021+Census+overview|url-status=live}}</ref> The census is the largest and most significant statistical event in Australia and is run by the [[Australian Bureau of Statistics]] (ABS).<ref name="2016 Census release">{{Cite web|last=Kalisch|first=David|date=2 July 2017|title=2016 Census of Population and Housing data release national media conference|url=https://www.youtube.com/watch?v=cpD6S2SxiKA|access-date=2 August 2020|website=YouTube|archive-date=22 October 2020|archive-url=https://web.archive.org/web/20201022001924/https://www.youtube.com/watch?v=cpD6S2SxiKA&gl=US&hl=en|url-status=live}}</ref> Every person must complete the census, although some personal questions are not compulsory.<ref>{{cite web|url=http://www.abs.gov.au/websitedbs/censushome.nsf/home/2011%20Census%20-%20Census%20Help%20-%20About%20the%20Census|title=2011 Census: Census help: About the Census|date=16 July 2011|work=[[Australian Bureau of Statistics]]|publisher=Australian Government|access-date=5 August 2011|archive-url=https://web.archive.org/web/20110929185539/http://www.abs.gov.au/websitedbs/censushome.nsf/home/2011%20Census%20-%20Census%20Help%20-%20About%20the%20Census|archive-date=29 September 2011}}</ref> The penalty for failing to complete the census after being directed to by the [[Australian Statistician]] is one federal [[penalty unit]], or {{AUD|220}}.<ref>{{Cite web|date=28 October 2016|title=Census and Statistics Act 1905|url=https://www.legislation.gov.au/Details/C2016C01005|access-date=2 August 2020|website=Federal Register of Legislation|archive-date=4 August 2020|archive-url=https://web.archive.org/web/20200804231731/https://www.legislation.gov.au/Details/C2016C01005|url-status=live}}</ref> The ''Australian Bureau of Statistics Act 1975'' and ''Census and Statistics Act 1905'' authorise the ABS to collect, store, and share anonymised data.<ref name="ABS Privacy">{{Cite web|url=http://www.abs.gov.au/websitedbs/D3310114.nsf/Home/Privacy,%20confidentiality%20&%20security|title=Privacy, Confidentiality and Security|date=22 February 2018|website=Australian Bureau of Statistics|access-date=25 March 2021|archive-date=9 March 2021|archive-url=https://web.archive.org/web/20210309005729/https://www.abs.gov.au/websitedbs/D3310114.nsf/Home/Privacy%2C%20confidentiality%20%26%20security|url-status=live}}</ref>

The [[1911 Australian census|first Australian census]] was held on 2 April 1911,<ref>{{cite news |date=20 November 2009 |title=Marking 100 years of Australian Censuses |url=http://www.abs.gov.au/ausstats/abs@.nsf/Latestproducts/2008.0Media%20Release12011?opendocument&tabname=Summary&prodno=2008.0&issue=2011&num=&view= |url-status=dead |archive-url=https://web.archive.org/web/20120425093406/http://www.abs.gov.au/AUSSTATS/abs@.nsf/Latestproducts/2008.0Media%20Release12011?opendocument&tabname=Summary&prodno=2008.0&issue=2011&num=&view= |archive-date=25 April 2012 |access-date=27 January 2012 |work=Australian Bureau of Statistics |publisher=Australian Government}}</ref> but census data had been previously collected by individual states.

The [[2021 Australian census|most recent census]] was held on 10 August 2021.<ref>{{Cite web|url=https://www.abs.gov.au/statistics/research/2021-census-topics-and-data-release-plan|title=2021 Census topics and data release plan &#124; Australian Bureau of Statistics|date=16 November 2020|website=www.abs.gov.au}}</ref> The next census will be held in early August 2026.

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==Geographical divisions==
The census, like all ABS data, is collected and published in geographical divisions as defined by the ''Australian Statistical Geography Standard'' (''ASGS''). The ASGS was released in 2011, replacing the former ''Australian Standard Geographical Classification''. The Standard is reviewed and updated every five years to align with the census. The ABS also releases data divided into areas not managed by the Bureau, such as [[Postcodes in Australia|postcodes]] (managed by [[Australia Post]]) and [[Local government in Australia|Local Government Areas]] (managed by state and territory governments).<ref>{{Cite web|date=11 June 2020|title=Australian Statistical Geography Standard|url=https://www.abs.gov.au/websitedbs/d3310114.nsf/home/australian+statistical+geography+standard+(asgs)|access-date=2 August 2020|website=Australian Bureau of Statistics|archive-date=26 July 2020|archive-url=https://web.archive.org/web/20200726131900/https://www.abs.gov.au/websitedbs/D3310114.nsf/home/Australian+Statistical+Geography+Standard+%28ASGS%29|url-status=live}}</ref>

==Privacy==
The ''Census and Statistics Act 1905'' and ''[[Privacy Act 1988]]'' prohibit the ABS from releasing any personally identifiable census data to any government, private or individual entity.<ref>{{Cite web|date=16 April 2020|title=Privacy, Confidentiality & Security|url=https://www.abs.gov.au/websitedbs/D3310114.nsf/Home/Privacy,%20confidentiality%20&%20security|access-date=2 August 2020|website=Australian Bureau of Statistics|archive-date=4 August 2020|archive-url=https://web.archive.org/web/20200804145252/https://www.abs.gov.au/websitedbs/D3310114.nsf/Home/Privacy%2C%20confidentiality%20%26%20security|url-status=live}}</ref>

In 1979, the [[Australian Law Reform Commission]] released ''Privacy and the Census'', a report detailing legislative privacy measures related to the census.<ref name="ALRC1979">{{cite web|year=1979|url=http://www.austlii.edu.au/au/other/alrc/publications/reports/12/12.pdf|archive-url=https://wayback.archive-it.org/all/20060723175516/http://www.austlii.edu.au/au/other/alrc/publications/reports/12/12.pdf|url-status=dead|archive-date=23 July 2006|title=Privacy and the Census, The Law Reform Commission, Report number 12|publisher=[[Australian Government Publishing Service]]|access-date=26 June 2006}}</ref> One of the key elements under question was the inclusion of names and addresses in census data. It was found that excluding names reduced the accuracy of the data; individuals were more likely to leave questions blank. Not collecting this data would also impair the ability of the ABS to ensure that all participants have responded.<ref name="ABSCensusHist2005">{{cite web|url=http://www.abs.gov.au/Ausstats/abs@.nsf/Previousproducts/1301.0Feature%20Article92005?opendocument&tabname=Summary&prodno=1301.0&issue=2005&num=&view=|title=The population census – a brief history|year=2005|work=1301.0 – Year Book Australia, 2005|publisher=[[Australian Bureau of Statistics]]|access-date=25 June 2006}}</ref>

The ABS protects personal information primarily through anonymisation of data. Personal information is stored separately from other census data, and separately from each other. Names are mutated into anonymised codes, which are then used to link data.<ref name="ABS Privacy" />

===Destruction of personal information===
Historically, the ABS has destroyed census forms or other census-related personal information after the census data processing period, roughly 18 months after the census.<ref name="ABS Privacy" />

Following a public consultation process before the 2016 census, it was found that Australians expected the ABS to hold their information for as long as there is a benefit to the community, and should be destroyed as soon as that need no longer exists. Following this process, the ABS has revised the retention period to four years after census, instead of 18 months. Concurrently, the ABS also improved their anonymisation techniques and limits access to addresses and anonymised names to when only necessary.<ref name="ABS Privacy" />

===Census Time Capsule===
Since 2001, the ABS and [[National Archives of Australia]] have given respondents the option to have their complete census data, including name and address, stored in the Census Time Capsule. The capsule is stored securely at the National Archives for 99 years after each census and is released publicly at the end of that period. The first capsule opening will be on 7 August 2100.<ref name="ABS Privacy" />

==Counting of Indigenous Australians==
{{main|1967 Australian referendum (Aboriginals)}}
[[Indigenous Australians]] in contact with the colonists were enumerated at many of the colonial censuses.<ref name="Smith, LR 1980">{{cite book|author=Smith, L. R.|date=1980|title=The Aboriginal Population of Australia|location=Canberra|publisher=Australian National University Press}}</ref> When the [[Federation of Australia]] occurred in 1901, the new [[Constitution of Australia|Constitution]] contained a provision (section 127), which said: "In reckoning the numbers of the people of the Commonwealth, or of a State or other part of the Commonwealth, Aboriginal [persons{{nbsp}}...] shall not be counted." In 1967, a [[Australian referendum, 1967 (Aboriginals)|referendum]] was held which approved two amendments to the Australian constitution relating to Indigenous Australians. The second of the two amendments deleted section 127 from the Constitution. It was widely believed at the time of the referendum, and is still often said, that section 127 meant that Aboriginal persons were not counted in Commonwealth censuses before 1967. In fact section 127 related to calculating the population of the states and territories for the purpose of allocating seats in Parliament and ''per capita'' Commonwealth grants. Its purpose was to prevent [[Queensland]] and [[Western Australia]] using their large Aboriginal populations to gain extra seats or extra funds.<ref name="Smith, LR 1980"/> Thus the Commonwealth Bureau of Census and Statistics interpreted section 127 as meaning that they may enumerate Aboriginal persons but that they must be excluded from published tabulations of population. Aboriginal persons living in settled areas were counted to a greater or lesser extent in all censuses before 1967.

[[George Handley Knibbs]], the first [[Australian Statistician|Commonwealth Statistician]], obtained a legal opinion at the time that persons of 50 percent or more non-Aboriginal descent were not Aboriginal persons for the purposes of the Constitution.{{efn |This could have been considered offensive because no consideration was given to (1) how the person themself identified, nor (2) whether or not the person was accepted as such by the community in which they lived.<ref name="kor21">{{cite web |title=Aboriginal Identity: Who is 'Aboriginal'? |first=Jens |last=Korff |date=2021-08-23 |website=Creative Spirits |url=https://www.creativespirits.info/aboriginalculture/people/aboriginal-identity-who-is-aboriginal |access-date=2022-07-12 }}</ref> When the person does not identify, or the community does not accept the person, as such, it is also a violation of [[wikisource:Universal_Declaration_of_Human_Rights#Article_20|article 20]] of the [[Universal Declaration of Human Rights]]. }} At the first Australian census in 1911 only those Aboriginal persons living near white settlements were enumerated, and the main population tables included only those of 50 percent or more non-Aboriginal descent. Details of Aboriginal persons of 50 percent or more non-Aboriginal descent were included in separate tables to Aboriginal persons of more than 50 percent Aboriginal descent.<ref name="STATS">{{cite web |last=Madden |first=Richard |author2=Al-Yaman, Fadwa |year=2003 |url=http://www.aiatsis.gov.au/__data/assets/pdf_file/5606/Madden.pdf |title=How Statisticians Describe Aboriginal and Torres Strait Islander Peoples |work=2003 Seminars on Health and Society: An Australian Indigenous Context |publisher=[[Australian Institute of Aboriginal and Torres Strait Islander Studies]] |access-date=25 June 2006 |url-status=dead |archive-url=https://web.archive.org/web/20060723175512/http://www.aiatsis.gov.au/__data/assets/pdf_file/5606/Madden.pdf |archive-date=23 July 2006 }}</ref> This practice was followed in all subsequent censuses up to 1966.

Since 1967, the ABS has considered [[Torres Strait Islanders]] a separate Indigenous people.<ref name="Ross">{{cite book |last1=Ross |first1=Kate |title=Population Issues, Indigenous Australians, 1996 |date=1999 |publisher=Australian Bureau of Statistics |location=Canberra |isbn=0642256845 |page=5 |id=4708.0 - Occasional Paper |url=https://www.ausstats.abs.gov.au/ausstats/free.nsf/0/F791BDC99C58DD87CA256ADA000448AB/$File/47080_1996.pdf |access-date=16 August 2020 |archive-date=10 March 2020 |archive-url=https://web.archive.org/web/20200310135103/https://www.ausstats.abs.gov.au/ausstats/free.nsf/0/F791BDC99C58DD87CA256ADA000448AB/$File/47080_1996.pdf |url-status=live }}</ref> Prior to 1947, Torres Strait Islanders were regarded as Aboriginal and excluded when not of 50 percent or more non-Aboriginal descent.<ref name="Ross"/> In 1947, Torres Strait Islanders were considered to be [[Polynesians|Polynesian]] and in 1954 and 1961 were considered to be [[Pacific Islander]]s.<ref name="Ross"/> In 1966, Torres Strait Islanders were again regarded as Aboriginal and excluded when not of 50 percent or more non-Aboriginal descent.<ref name="Ross"/>

==Australian Standard Classification of Cultural and Ethnic Groups==
Ancestry data was included in the [[#1986|1986]] census. It was found when the data was evaluated that people who filled in the census were not sure what the question meant and there were inconsistent results, particularly for those people whose families had been in Australia for many generations. There were no ancestry related questions in [[#1991|1991]] or [[#1996|1996]]. For [[#2001|2001]] it was decided that development of Government policies did need information about people who were either born overseas, or whose parents were born overseas. The questions were to mark the ancestries most closely identified with and to consider ancestry back as far as three generations. Respondents had the option of reporting more than one ancestry but only the first two ancestries they reported were coded for the census.

The results for 2001 were coded using the Australian Standard Classification of Cultural and Ethnic Groups (ASCCEG). This classification of cultural and ethnic groups is based on the geographic area in which a group originated or developed; and the similarity of cultural and ethnic groups in terms of social and cultural characteristics. The classification is specific to Australian needs and was developed by the Australian Bureau of Statistics. The classification is based on the self-perceived group identification approach, using a self assessed response to a direct question. This approach measures the extent to which individuals associate with particular cultural or ethnic groups.<ref name="Ancestry2001">{{cite web|year=2002|url=http://www.abs.gov.au/AUSSTATS/abs@.nsf/ProductsbyReleaseDate/A7A0E94399353F1DCA257148008018DC?OpenDocument|title=2970.0.55.006 – 2001 Census of Population and Housing – Fact Sheet: Ancestry, 2001|work=Australian Bureau of Statistics|publisher=Australian Government|access-date=23 August 2006|archive-date=6 September 2006|archive-url=https://web.archive.org/web/20060906195207/http://abs.gov.au/AUSSTATS/abs@.nsf/ProductsbyReleaseDate/A7A0E94399353F1DCA257148008018DC?OpenDocument|url-status=live}}</ref><ref>{{cite web|year=2000|url=http://www.ausstats.abs.gov.au/ausstats/free.nsf/0/CAFD9A578C421AEFCA256C0F0001D603/$File/12490_2000-01.pdf|title=Australian Standard Classification of Cultural and Ethnic Groups (ABS Catalogue no. 1249.0)|pages=176|work=Australian Bureau of Statistics|publisher=Australian Government|access-date=23 August 2006|archive-date=23 August 2006|archive-url=https://web.archive.org/web/20060823181432/http://www.ausstats.abs.gov.au/ausstats/free.nsf/0/CAFD9A578C421AEFCA256C0F0001D603/$File/12490_2000-01.pdf|url-status=live}}</ref>

==History==
===1828===
{{main|1828 New South Wales census}}
Australia's first census was held in November 1828 in [[New South Wales]], a British colony at the time. Previous government statistical reports had been taken from "musters" where white immigrants were brought together for counting. In 1828, the white population was 36,598: 20,870 settlers and 15,728 convicts. 23.8% of the population were born in the colony and 24.5% were women. There were 25,248 Protestants and 11,236 Catholics. [[Indigenous Australians]] were not counted.<ref name = "1881Events">{{cite book|editor1=Aplin, Graeme|editor2=Foster, S. G.|editor3=McKernan, Michael|title=Australians: Events and Places|year=1987|publisher =Fairfax, Syme & Weldon Associates|location=Broadway, New South Wales, Australia|isbn=0-949288-13-6|pages=38, 97}}</ref>

Of the 36,598 people, 638 were living in what is now [[Queensland]]. There were also 18,128 people in [[Tasmania]].<ref name = "popstats">{{cite book|editor=Vamplew, Wray|title=Australians: Historical Statistics|year=1987|publisher=Fairfax, Syme & Weldon Associates|location=Broadway, New South Wales, Australia|isbn=0-949288-29-2|page=26}}</ref>

===1881===
In the mid-19th century the colonial statisticians encouraged compatibility between the colonies in their respective censuses, and in 1881 a census was held simultaneously in each of the colonies.<ref name="ABSCensusHist2005"/> This was part of a census of the [[British Empire]]. The questions posed in the colonies were not uniform and [[Henry Heylyn Hayter]], who conducted the Victorian census, found that this caused difficulties in dealing with Australia-wide data.

The population of Australia counted in the census was 2,231,531. <ref name="Historical-Population">{{cite web |url=https://www.abs.gov.au/statistics/people/population/historical-population/latest-release |title=Historical Population |author=<!--Not stated--> |date=18 April 2016 |website= |publisher=[[Australian Bureau of Statistics]] |access-date=5 July 2021}}</ref>

{|class="wikitable" style="margin: 1em auto 1em auto"
|+1881 census population results<ref name="Historical-Population"/>
!New South Wales
!Victoria
!Queensland
!Tasmania
!South Australia*
!Western Australia
!'''Australia'''
|-
|741,412
|858,605
|211,040
|114,790
|276,393
|29,561
|'''2,231,531'''
|}

At the time, the Northern Territory was part of South Australia and had 3,451 white people plus 6,346 Aboriginals in settled districts. Including the Northern Territory, South Australia had a total counted population of 286,211 people. The reported population of Western Australia did not include Aboriginal persons of more than 50 percent Aboriginal descent.<ref name = "1881Events"/> The population of greater [[Melbourne]] was 282,947 and of Sydney was 224,939.<ref name = "1881Events"/>

===1891===
{|class="wikitable" style="margin: 1em auto 1em auto"
|+ '''1891 census population results'''<ref name="Historical-Population"/>
!New South Wales
!Victoria
!Queensland
!Tasmania
!South Australia*
!Western Australia
!'''Australia'''
|-
|1,153,170
|1,158,372
|400,395
|151,150
|324,721
|53,177
|'''3,240,985'''
|}

===1901===
In 1901, there were 3,773,801 people (1,977,928 males and 1,795,873 females) counted in Australia.<ref name="ABS1901AustSnapshot">{{cite web|year=2002|url=http://www.abs.gov.au/Websitedbs/D3110124.NSF/24e5997b9bf2ef35ca2567fb00299c59/c4abd1fac53e3df5ca256bd8001883ec!OpenDocument|title=2001 Census of Population and Housing – 00 1901 Australian Snapshot|work=Australian Bureau of Statistics|publisher=Australian Government|access-date=26 June 2006|archive-date=1 October 2007|archive-url=https://web.archive.org/web/20071001000055/http://www.abs.gov.au/Websitedbs/D3110124.NSF/24e5997b9bf2ef35ca2567fb00299c59/c4abd1fac53e3df5ca256bd8001883ec!OpenDocument|url-status=live}}</ref>

Prior to [[Federation of Australia|federation]], each colony had been responsible for its own census collection. The census held during the first year of Federation, 1901, was again collected by each state separately. When planning for the 1901 census it was clear that federation was soon to occur, and a uniform census schedule was adopted.<ref name="ABSCensusHist2005"/>

===1911===
{{main|1911 Australian census}}
The first national census was developed by the Commonwealth Bureau of Census and Statistics. The census occurred at midnight between 2 and 3 April 1911. Tabulation was carried out almost entirely by hand; over 4&nbsp;million cards were sorted and physically counted for each tabulation. Results from the 1911 census took a long time to be released, with delays increased by [[World War I]].<ref name="ABSCensusHist2005"/> The Australian population was counted in the census as 4,455,005, exclusive of Aboriginal persons of more than 50 percent Aboriginal descent.

In the 1911 census, many collectors used horses. A drought in Western Australia meant that some collectors were unable to find feed for their horses. Flooding and bogs stranded some collectors in Queensland.<ref name="LaunchRecruit2006">{{cite speech|author-link=Chris Pearce (politician)|author=Pearce, Chris|year=2006|url=http://parlsec.treasurer.gov.au/cjp/content/speeches/2006/005.asp|title=ABS 2006 Census Recruitment Campaign Launch|work=Parliamentary Secretary to the Treasurer|publisher=Australian Government|location=Canberra|access-date=25 June 2006|archive-url=https://web.archive.org/web/20060820233828/http://parlsec.treasurer.gov.au/cjp/content/speeches/2006/005.asp|archive-date=20 August 2006|url-status=dead|df=dmy-all}}</ref>

====Rubella research====
In 1911 the census asked about [[Deaf-mute|deaf-mutism]]. This question was also asked in the next two censuses of 1921 and 1933. Deaf-mutism was found to be very high among 10- to 14-year-olds, with the same pattern existing in the 1921 census among 20- to 24-year-olds. The statisticians report on the 1921 census noted that it was "a reasonable assumption therefore that the abnormal number of deaf-mutes . . . was the result of the extensive epidemic of infectious diseases which occurred soon after many in those age groups were born".  [[Rubella]] was not known to be a possible contributor. During [[World War II]], the ophthalmologist [[Norman McAllister Gregg]] began to investigate the connection between birth defects and the infection of mothers early in their pregnancy. In 1951, prompted by Gregg's work, Australian statistician Oliver Lancaster examined the census figures of 1911, 1921 and 1933. He found a peak in the level of deaf-mutism in the age cohort born in 1898 and 1899 and that this matched with a known outbreak of rubella in those years. "This was the first time in the world that the link between rubella and congenital problems with unborn children was firmly established."<ref name="LaunchRecruit2006"/>

===1921{{Ndash}}1966===
[[File:AustralianCensus1921.jpg|thumb|300px|Lantern slide produced for the [[Australian Inland Mission]] based on the 1921 census. It shows the Australian population enumerated in the census graded for population density.]]
Australia's population counted in April 1921 was 5,435,700, exclusive of Aboriginal persons of more than 50 percent Aboriginal descent. The Statistician independently estimated the number of Aboriginal persons, both those of more than 50 percent Aboriginal descent and those of 50 percent or more non-Aboriginal descent, by obtaining figures from police and protectors of Aboriginal persons throughout the country.

One of the significant findings of the 1921 census was the low rate of males to females in the 20–30 age group, showing the impact of World War I on the population.<ref name="ABS2006CensusArticles">{{cite web|year=2005|url=http://www.abs.gov.au/Websitedbs/D3110124.NSF/5b50249f2d88db6eca256de4002c508f/8951e990e468bae9ca2570ce0075750c!OpenDocument|title=Census of Population and Housing – 2006 Census articles|work=Australian Bureau of Statistics|publisher=Australian Government|access-date=25 June 2006|archive-date=30 September 2007|archive-url=https://web.archive.org/web/20070930194405/http://www.abs.gov.au/Websitedbs/D3110124.NSF/5b50249f2d88db6eca256de4002c508f/8951e990e468bae9ca2570ce0075750c!OpenDocument|url-status=live}}</ref>

The 1921 census introduced automatic machine tabulation equipment, hired from England for the census.<ref name="ABSCensusHist2005"/> Three punched cards were used to store individual, dwelling, and family information. The cards were processed using an electric sorting machine prior to final totalling with an electric tabulator machine, devised by [[Herman Hollerith]].<ref name="IBM">{{cite web|year=2004|url=http://www-8.ibm.com/au/70years/more_detail/1966.html|title=1966 – IBM computers used to process census data for the first time|work=About IBM in Australia|publisher=IBM|access-date=25 June 2006|archive-date=22 November 2005|archive-url=https://web.archive.org/web/20051122043813/http://www-8.ibm.com/au/70years/more_detail/1966.html|url-status=dead}}</ref>

The census was subsequently conducted in 1933, 1947, 1954, and every five years from 1961 onwards.

===1971===
Following the [[Australian referendum, 1967 (Aboriginals)|1967 referendum]] removing [[Section 127 of the Australian Constitution|section 127 from the Constitution]], the "race" question was re-designed for the 1971 census and methods for remote area collection examined to improve identification of Indigenous Australian groups.<ref name= "ABSCensusHist2005" />

There were 12,755,638 people counted.<ref name = "popstats"/>

===1976===
The 1976 census was the largest undertaken to date, with 53 questions. Due to budgetary restraints, the ABS was not able to complete normal processing of the data and a 50% sample was processed.<ref name= "ABSCensusHist2005"/> There were 13,548,450 people counted.<ref name = "popstats"/>

===1981===
Scanned data of the 1981 Census is available on the ABS website.<ref>{{cite web | title=2103.0 | website=Census of Population and Housing, 1981 | date=25 March 2009 | url=https://www.abs.gov.au/ausstats/abs@.nsf/productsbyCatalogue/B4B38C5D358CFEAECA25758400151EE1?OpenDocument | access-date=18 October 2020 | archive-date=20 October 2020 | archive-url=https://web.archive.org/web/20201020020940/https://www.abs.gov.au/ausstats/abs@.nsf/productsbyCatalogue/B4B38C5D358CFEAECA25758400151EE1?OpenDocument | url-status=live }}</ref>

===1986===
The 1986 Census was held on 30 June 1986. Scanned data of the 1986 Census is available on the ABS website.<ref>{{cite web | title=2102.0 | website=Census of Population and Housing, 1986 | date=17 March 2009 | url=https://www.abs.gov.au/AUSSTATS/abs@.nsf/Lookup/2102.0Main+Features11986?OpenDocument | access-date=18 October 2020 | archive-date=18 October 2020 | archive-url=https://web.archive.org/web/20201018140646/https://www.abs.gov.au/AUSSTATS/abs@.nsf/Lookup/2102.0Main+Features11986?OpenDocument | url-status=live }}</ref>

===1991===
The 1991 census was held on 6 August 1991.<ref>[http://www.ausstats.abs.gov.au/ausstats/free.nsf/0/DF58A4D8AFE1AD39CA25722500049472/$File/29100_1991.pdf Directory of Census Statistics] {{Webarchive|url=https://web.archive.org/web/20170228082216/http://www.ausstats.abs.gov.au/ausstats/free.nsf/0/DF58A4D8AFE1AD39CA25722500049472/$File/29100_1991.pdf |date=28 February 2017 }}, Cat. No. 2910.0, Australian Bureau of Statistic, January 1995</ref>

===1996===
The 1996 census was held on 6 August. There were 16,892,423 people counted in Australia. Of these, 342,864 people identified themselves as Indigenous Australians. There were 139,594 overseas visitors.<ref name="ABSPrevCensuses">{{cite web|year=2006|url=http://www.abs.gov.au/websitedbs/d3310114.nsf/home/Previous%20Censuses:%20Census%20data|title=Previous Censuses: Census Data|work={{CensusAU|2006}}|publisher=[[Australian Bureau of Statistics]]|access-date=26 June 2006|archive-url=https://web.archive.org/web/20060819043932/http://www.abs.gov.au/websitedbs/d3310114.nsf/home/Previous%20Censuses:%20Census%20data|archive-date=19 August 2006|url-status=dead}}</ref>

===2001===
The 2001 census was held on 7 August. There were 18,769,420 people counted in Australia.<ref>{{Census 2001 AUS|id=0|name=Australia|accessdate=24 January 2016|quick=on}}</ref> Of these, 410,003 people identified as Indigenous Australians. There were 203,101 overseas visitors.<ref name="ABSPrevCensuses"/>

===2006===
The 2006 census was conducted on the night of 8 August. There were 19,855,288 people counted in Australia. Of those, 455,031 people identified as Indigenous Australians. There were 206,358 overseas visitors.<ref name="ABSPrevCensuses"/> For the first time, the territories of Cocos (Keeling) Islands were included in the 2006 census, following the enactment of the ''Territories Law Reform Act 1992''.<ref name="ABSCensus2011NatureContent"/>

The 2006 census contained 60 questions, all of which were compulsory except those relating to religion and household census data retention. The census cost around {{AUD}}300&nbsp;million to conduct.

===={{Proper name|eCensus}}====
For the first time, respondents were given the option of completing an online "{{Proper name|eCensus}}" as opposed to the traditional paper-based version. By 17 August, more than 720,000 households had completed the census online.<ref name="17AugEcensus">{{cite press release|url=http://www.abs.gov.au/AUSSTATS/abs@.nsf/mediareleasesbyReleaseDate/4C85D1995909281FCA2571CD000F74D9?OpenDocument|title=IBM application and hosting expertise helps ABS build the big picture faster with eCensus program|publisher=Australian Bureau of Statistics|date=17 August 2006|access-date=22 August 2006|archive-date=12 September 2006|archive-url=https://web.archive.org/web/20060912202720/http://www.abs.gov.au/AUSSTATS/abs@.nsf/mediareleasesbyReleaseDate/4C85D1995909281FCA2571CD000F74D9?OpenDocument|url-status=live}}</ref>

Across Australia, 8.4% of estimated dwellings lodged online. The highest percentage of internet lodgements was in the [[Australian Capital Territory]] with 14.8% of households using {{Proper name|eCensus}}. This was a markedly different proportion of households than elsewhere in Australia, with the other states and territory ranging from 5.9% in the [[Northern Territory]] to 8.9% in [[Western Australia]].<ref name="17AugEcensus" />

The peak lodgement was between 8pm and 9pm on census night, when more than 72,000 online forms were received. The {{Proper name|eCensus}} remained available throughout the entire census period. During the 24-hour period of 8 August (census night), {{Proper name|eCensus}} delivered more than 12.5 million page views and at 8:47 pm, more than 55,000 households were logged on simultaneously. [[IBM]] assisted with the development of the {{Proper name|eCensus}}, having provided similar infrastructure and technology for the [[Canada 2006 Census|Canadian census]] earlier that year.<ref name="17AugEcensus" />

===2011===
The 2011 census was held on the night of 9 August, using both paper and electronic "{{Proper name|eCensus}}" forms. Minimal changes were made from the 2006 census due to financial constraints on the ABS during development.<ref name="ABSCensus2011NatureContent">{{cite web|year=2008|url=http://www.abs.gov.au/ausstats/subscriber.nsf/log?openagent&20080_2011.pdf&2008.0&Publication&410FDD3C31C0BE1FCA257673001BFC61&&2011&20.11.2009&Latest|title=Census of Population and Housing: Nature and Content, 2011|work={{CensusAU|2011}}|publisher=[[Australian Bureau of Statistics]]|access-date=12 February 2011}}</ref> The 2011 census was the largest logistical peacetime operation ever undertaken in Australia, employing over 43,000 field staff to ensure approximately 14.2&nbsp;million forms were delivered to 9.8&nbsp;million households.<ref name="ABSwhatis">{{cite web |date=15 May 2014 |url=http://www.abs.gov.au/websitedbs/censushome.nsf/home/what?opendocument&navpos=110 |title=About the Census: What is the Census? |work=[[Australian Bureau of Statistics]] |publisher=Australian Government |access-date=6 January 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150124131256/http://www.abs.gov.au/websitedbs/censushome.nsf/home/what?opendocument&navpos=110 |archive-date=24 January 2015 |df=dmy }}</ref>

The first results of the census were released in June 2012 on the Australian Bureau of Statistics website.<ref>{{cite news|url=http://www.censusdata.abs.gov.au/census_services/getproduct/census/2011/quickstat/0|title=2011 Census QuickStats: Australia|work=[[Australian Bureau of Statistics]]|publisher=Australian Government|date=10 October 2012|access-date=24 January 2013|archive-date=6 November 2015|archive-url=https://web.archive.org/web/20151106221006/http://www.censusdata.abs.gov.au/census_services/getproduct/census/2011/quickstat/0|url-status=live}}</ref>

The cost of the 2011 census was {{AUD}}440 million.<ref name="TheAge180215">{{cite web|last=Martin|first=Peter|date=19 February 2015|title=Abbott government considers axing the Australian census to save money|url=http://www.theage.com.au/federal-politics/political-news/abbott-government-considers-axing-the-australian-census-to-save-money-20150218-13ieik.html|access-date=9 August 2016|work=theage.com.au|archive-date=31 May 2016|archive-url=https://web.archive.org/web/20160531115931/http://www.theage.com.au/federal-politics/political-news/abbott-government-considers-axing-the-australian-census-to-save-money-20150218-13ieik.html|url-status=live}}</ref>

===2016===
{{main|2016 Australian census}}
[[File:Census in Australia 2016, ABS website error.png|thumb|ABS website message after the 2016 online census was shut down]]
The census occurred on 9 August 2016. For the first time, the ABS the census was by default filled out online, claiming it expected more than 65% of Australians would be completing the census online.<ref>{{cite web| title=Get ready to get digital with the 2016 Census| url=http://www.abs.gov.au/ausstats/abs@.nsf/mediareleasesbyReleaseDate/EC8D47BE72A97E7ECA257E9A00131583?OpenDocument| date=9 August 2015| publisher=Australian Bureau of Statistics| author=Media Release| access-date=15 August 2016| archive-date=16 August 2016| archive-url=https://web.archive.org/web/20160816063328/http://www.abs.gov.au/ausstats/abs@.nsf/mediareleasesbyReleaseDate/EC8D47BE72A97E7ECA257E9A00131583?OpenDocument| url-status=live}}</ref> Reflecting this new preference, the tagline of the ad campaign for the census was the rhyming slogan "Get online on August 9".<ref>{{cite web|title=Official Ad From Australian Beauro of Statistics|website = [[YouTube]]|url=https://youtube.com/qQEZbVzomec?t=21s}} {{Dead link|date=November 2018 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Across many regions, paper forms were no longer delivered by default to homes, and households that wished to complete a paper census had to order such forms via an automated hotline. Letters were sent to each dwelling with unique code numbers that people would need to either login to the census website or order a paper form if they preferred. By census night, many households had still not received such a letter.<ref>{{Cite news|url=https://www.dailymercury.com.au/news/census-delay-for-residents-without-letters/3074116/|title=Census delay for residents without letters|last=Smith|first=Lucy|date=August 9, 2016|work=Mackay Daily Mercury|access-date=2018-02-11|language=en|archive-date=11 February 2018|archive-url=https://web.archive.org/web/20180211132109/https://www.dailymercury.com.au/news/census-delay-for-residents-without-letters/3074116/|url-status=live}}</ref> Contrary to previous years where censuses were both delivered and retrieved from households by dedicated census employees, in 2016 most of the paperwork relating to the census was delivered from and to the ABS by [[Australia Post]].

The 2016 census was met by two controversies. The first was that the retention of names and addresses increased to up to 4 years, from 18 months in the 2006 and 2011 censuses, leading to concerns about privacy and data security. As such, some [[Australian Senate]] [[crossbencher]]s (from the [[Australian Greens|Greens]], [[Nick Xenophon Team]] and [[Jacqui Lambie Network]]) said they would not complete those specific sections of the census, despite the fines associated with incorrect completion of the census.<ref>{{cite news|url=http://www.abc.net.au/news/2016-08-09/scott-ludlam-wont-put-name-on-census-form/7703380|title=Census 2016: Christopher Pyne criticises politicians withholding details over privacy fears|work=[[ABC News (Australia)|ABC News]]|location=Australia|date=9 August 2016|author=Anderson, Stephanie|access-date=18 August 2016|archive-date=15 August 2016|archive-url=https://web.archive.org/web/20160815091103/http://www.abc.net.au/news/2016-08-09/scott-ludlam-wont-put-name-on-census-form/7703380|url-status=live}}</ref> The second was that many Australians could not complete the census online on the designated day.<ref>{{cite news|url=http://www.abc.net.au/news/2015-08-09/2016-census-to-be-delivered-online-for-speed-and-convenience/6682732|title=Census goes digital: 2016 survey to be delivered online for speed, convenience|work=[[ABC News (Australia)|ABC News]]|location=Australia|date=9 August 2015|author=Borrello, Eliza|access-date=9 August 2015|archive-date=9 August 2015|archive-url=https://web.archive.org/web/20150809215724/http://www.abc.net.au/news/2015-08-09/2016-census-to-be-delivered-online-for-speed-and-convenience/6682732|url-status=live}}</ref> While a paper census form was also available on request, for 2016 the ABS was aiming for two-thirds online.<ref name=smh-census-digital>{{cite news |url=http://www.smh.com.au/federal-politics/political-news/census-2016-to-be-100-million-cheaper-and-all-digital-on-august-9-20150808-giumyh.html |title=Census 2016 to be $100 million cheaper and all digital, on August 9 |date=9 August 2015 |newspaper=[[The Sydney Morning Herald]] |author=Martin, Peter |access-date=9 August 2015 |archive-date=8 August 2015 |archive-url=https://web.archive.org/web/20150808234203/http://www.smh.com.au/federal-politics/political-news/census-2016-to-be-100-million-cheaper-and-all-digital-on-august-9-20150808-giumyh.html |url-status=live }}</ref> However, the online census website shut down at about 7:30 pm AEST on the night it was to be completed.

According to the ABS, throughout 9 August the census website received four [[denial-of-service attack]]s. At 7:30 pm, when the site was being heavily used, a software failure meant that the ABS was unable to keep blocking the denial-of-service attacks, leading to the failure of a router. As a result, the ABS decided to close down the system as a precaution. The ABS reported that no census data were compromised.<ref>{{cite news|title=Census: How the Government says the website meltdown unfolded|url=http://www.abc.net.au/news/2016-08-10/census-night-how-the-shambles-unfolded/7712964|access-date=11 August 2016|work=ABC News|date=10 August 2016|archive-date=10 August 2016|archive-url=https://web.archive.org/web/20160810113109/http://www.abc.net.au/news/2016-08-10/census-night-how-the-shambles-unfolded/7712964|url-status=live}}</ref><ref name="abs-census-back"/><ref>{{cite news |work=BBC News |url=https://www.bbc.co.uk/news/world-australia-37008173 |title=Australian census attacked by hackers |date=10 August 2016 |access-date=10 August 2016 |archive-date=10 August 2016 |archive-url=https://web.archive.org/web/20160810022306/http://www.bbc.co.uk/news/world-australia-37008173 |url-status=live }}</ref> The [[Australian Signals Directorate]] was assisting the ABS to bring the infrastructure back online more than 24 hours after the closure.<ref>{{Cite web|url=http://www.abc.net.au/news/2016-08-11/census-website-still-down-24-hours-after-crashing/7718584|title=Census website still down after cyber attacks|date=10 August 2016|website=ABC News|language=en-AU|access-date=10 August 2016}}</ref>

The census website was restored at 2:30 pm on 11 August.<ref name="abs-census-back">{{cite press release |title=2016 Census – Online form update: 3.00 pm, August 11 |url=http://www.abs.gov.au/AUSSTATS/abs@.nsf/mediareleasesbyReleaseDate/5239447C98B47FD0CA25800B00191B1A?OpenDocument |website=abs.gov.au |publisher=Australian Bureau of Statistics |access-date=11 August 2016 |date=11 August 2016 |archive-date=10 August 2016 |archive-url=https://web.archive.org/web/20160810110436/http://abs.gov.au/AUSSTATS/abs@.nsf/mediareleasesbyReleaseDate/5239447C98B47FD0CA25800B00191B1A?OpenDocument |url-status=live }}</ref> On the same day, Prime Minister [[Malcolm Turnbull]] stated his displeasure over the event, which had "been a failure of the ABS", with his expectation that "heads will roll" once a review was complete.<ref>{{Cite web|url=http://www.abc.net.au/news/2016-08-11/census-malcolm-turnbull-slams-abs-over-failure/7718584|title=Angry PM slams ABS 'failure' as census website goes back online|date=10 August 2016|website=ABC News|language=en-AU|access-date=11 August 2016|archive-date=11 August 2016|archive-url=https://web.archive.org/web/20160811164743/http://www.abc.net.au/news/2016-08-11/census-malcolm-turnbull-slams-abs-over-failure/7718584|url-status=live}}</ref> Leader of the opposition [[Bill Shorten]] said that the 2016 census had been the "worst-run ... in the history of Australia".<ref>{{cite news|url=http://www.news.com.au/finance/economy/australian-economy/census-2016-outage-labor-calls-for-census-minister-michael-mccormack-to-resign/news-story/7d8cd5bfaadfbc852311be165b0cc0b8|title=Census hacking: Privacy Commissioner investigates as Nick Xenophon calls for Senate inquiry|publisher=News Limited|date=10 August 2016|access-date=13 August 2016|author=Kara Vickery and Gemma Wilson|archive-date=12 August 2016|archive-url=https://web.archive.org/web/20160812181008/http://www.news.com.au/finance/economy/australian-economy/census-2016-outage-labor-calls-for-census-minister-michael-mccormack-to-resign/news-story/7d8cd5bfaadfbc852311be165b0cc0b8|url-status=live}}</ref> The ABS blamed service provider [[IBM]] for the failure in the online census, saying that IBM had advised on the preparedness and resilience to DDoS attacks and had not offered any further protections that could be employed.<ref>{{cite web|title=Census 2016: ABS targets service provider IBM over botched survey|url=http://www.abc.net.au/news/2016-09-23/abs-targets-service-provider-ibm-over-botched-census/7873034|website=ABC|date=23 September 2016|publisher=ABC|access-date=16 November 2016|archive-date=17 November 2016|archive-url=https://web.archive.org/web/20161117063250/http://www.abc.net.au/news/2016-09-23/abs-targets-service-provider-ibm-over-botched-census/7873034|url-status=live}}</ref> On 31 August, the [[Parliament of Australia]] initiated an inquiry into the 2016 census.<ref>{{cite web|title=2016 Census Inquiry|url=http://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Economics/2016Census|website=Australian Parliament House|publisher=Australian Parliament House|access-date=24 September 2016|archive-date=24 September 2016|archive-url=https://web.archive.org/web/20160924180056/http://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Economics/2016Census|url-status=live}}</ref> It released its findings on 24 November: no individual party was found to be responsible but it was shared between the government, IBM, and other sub-contractors.<ref>{{cite news|title=Government, IBM and ABS all criticised as census failure reports released|url=http://www.afr.com/technology/government-ibm-and-abs-all-criticised-as-census-failure-reports-released-20161124-gswzrv|access-date=26 November 2016|work=Australian Financial Review|date=24 November 2016|archive-date=25 November 2016|archive-url=https://web.archive.org/web/20161125133321/http://www.afr.com/technology/government-ibm-and-abs-all-criticised-as-census-failure-reports-released-20161124-gswzrv|url-status=live}}</ref>

The census forms were able to be submitted online until 23 September. Once collection was complete, the ABS issued an announcement which confirmed that in spite of the initial online problems, there was a preliminary response rate of more than 96%. This consisted of 4.9&nbsp;million (over 58%) online submissions and 3.5&nbsp;million paper forms. The preliminary response rate was similar to the previous two census response rates of 95.8% in 2006 and 96.5% in 2011.<ref>{{cite web|title=Australia records more than 96 per cent preliminary response rate for the 2016 Census|url=http://www.abs.gov.au/websitedbs/censushome.nsf/home/CO-108?opendocument&navpos=620|website=www.abs.gov.au|publisher=Australian Bureau of Statistics|date=11 October 2016|access-date=26 November 2016|language=en|archive-date=27 November 2016|archive-url=https://web.archive.org/web/20161127084641/http://www.abs.gov.au/websitedbs/censushome.nsf/home/CO-108?opendocument&navpos=620|url-status=live}}</ref>

According to the ABS, the preliminary release of census data became available to the public on the ABS website on 11 April 2017, two months earlier than for any previous census. The main release of data occurred on 27 June 2017 and a final data release on 17 October 2017.<ref>{{cite web |url=http://www.abs.gov.au/ausstats/abs@.nsf/mf/2011.0.55.001 |title=2011.0.55.001 – Information Paper: Census of Population and Housing – Products and Services, 2016 |author=<!--Staff writer(s); no by-line.--> |date=22 December 2016 |website=Australian Bureau of Statistics |publisher=Australian Bureau of Statistics |access-date=2 February 2017 |archive-date=20 January 2017 |archive-url=https://web.archive.org/web/20170120095745/http://www.abs.gov.au/ausstats/abs@.nsf/mf/2011.0.55.001 |url-status=live }}</ref>

===2021===
{{Main|2021 Australian census}}

The 2021 Census occurred on 10 August 2021, and was run by the Australian Bureau of Statistics (ABS). It was Australia's 18th Census. 

The 2021 Census achieved a response rate above the Australian Bureau of Statistics target obtaining data from 10 million (10,852,208) dwellings. The dwelling response rate was 96.1 per cent, up from 95.1 per cent in 2016.<ref>{{Cite web |date=2022-06-28 |title=2021 Census snapshot: Australia has doubled in size over the last 50 years {{!}} Australian Bureau of Statistics |url=https://www.abs.gov.au/media-centre/media-releases/2021-census-snapshot-australia-has-doubled-size-over-last-50-years |access-date=2023-03-09 |website=www.abs.gov.au |language=en}}</ref>

The Statistical Independent Assurance Panel, established by the Australian Statistician to provide assurance of Census data quality, concluded that the 2021 Census data is fit-for-purpose, is of comparable quality to the 2011 and 2016 Censuses and can be used with confidence.<ref>{{Cite web |date=2022-06-28 |title=Report on the quality of 2021 Census data: Statistical Independent Assurance Panel to the Australian Statistician {{!}} Australian Bureau of Statistics |url=https://www.abs.gov.au/census/about-census/census-statistical-independent-assurance-panel-report |access-date=2023-03-09 |website=www.abs.gov.au |language=en}}</ref>

The first release of the Census data was published on 28 June 2022. Census data can be accessed using a number of [https://www.abs.gov.au/census/find-census-data Census data tools].

==See also==
* [[Census and Statistics Act 1905]]
* [[Demography of Australia]]
* [[List of cities in Australia by population]]

==Notes==
{{reflist|group=lower-alpha}}

==References==
{{reflist}}

==Further reading==
* {{Cite web|url=http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/2071.0Feature+Article1July+2011|title=One hundred years of working on the census|date=1 March 2011|last=Wright|first=Beth|work=[[Australian Bureau of Statistics]]|publisher=Australian Government}}

==External links==
* {{Official website|abs.gov.au/census}}
* [http://www.abs.gov.au/ausstats/subscriber.nsf/log?openagent&2016%20census%20of%20population%20and%20housing%20sample%20household%20form.pdf&2900.0&Publication&0D6C87E13FC2A7E9CA2581470023D0B8&&2016&27.06.2017&Latest 2016 Census form (sample)]<!--Parent page, in case the specific one breaks in future: http://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/2900.02016?OpenDocument -->

[[Category:Censuses in Australia]]
[[Category:Demographics of Australia|Census]]
[[Category:Australian Bureau of Statistics]]