2016 Census Overview

The 2016 Census was Australia's 17th national Census of Population and Housing. It is the largest statistical collection undertaken by the Australian Bureau of Statistics. It aims to connect with every person in Australia to collect data on their key characteristics and the place they are staying in on Census night. While some of this information is available from other sources, only a Census can provide the information for the entire country, including small geographic areas and small population groups.

Since the first Census in 1911, the ABS has conducted high quality Censuses with an unblemished record of data security. More than 95% of Australians participated in the 2016 Census, indicating high quality data comparable to previous Censuses.

2016 Census data release dates

11 April 2017
A preview of the 2016 Census results was published on the ABS website giving insight into what makes the‘typical’ Australian at the national and state/territory level, showing what has changed over time.

27 June 2017
The first comprehensive Census dataset was released including national, State/Territory and capital city data for selected key person, family and dwelling characteristics including age, sex, religion, language and income. Community level Census data is available. Census data quality statements and the Independent Assurance Panel report were also released at this time.

October 2017
Detailed Census data was released on employment, qualifications and population mobility, including journey to work and internal migration.

Through 2018
Further five per cent sample from the 2016 Census added to the Australia Census Longitudinal Dataset, bringing together data from the 2006, 2011 and 2016 Censuses to create a research tool for exploring how Australian society is changing over time. Homelessness Estimates, Census Microdata, Socio-Economic Indexes For Areas (SEIFA) and commuting distance will also be progressively released.

How is Census data used?

Census is the definitive and often only source of data on small population groups and small geographic areas. Data collected in the 2016 Census will underpin $500 billion of Government funding to States, Territories and local governments over the next four years. It is critical to the setting of Commonwealth, state and local electoral boundaries. Census data is also used by individuals and organisations in the public and private sectors to make informed decisions on policy and planning issues that impact the lives of all Australians. Some great examples of how others have used Census data can be found here.

How do I know Census data is high quality?

High Participation
The final response rate for the 2016 Census of 95.1% is very high and comparable to the response to the 2006 and 2011 Censuses.

Post-Enumeration Survey
We significantly increased the sample size (more than 40,000 households) for the Post-Enumeration Survey, which is conducted after every Census to measure Census quality and produce high quality population estimates. The results of the Post Enumeration Survey, 2016 have now been released.

Data Quality Checks and Investigations
We have undertaken extensive and rigorous data quality assurance work. We review, monitor, and assess data quality through a number of steps, including analysing time series data and comparing answers within the form and with other data sources to identify fake and erroneous data.

Independent Assurance Panel
We established an independent panel of eminent Australian and international experts to review and assure the quality of statistical outputs from the 2016 Census. The Panel determined that 2016 Census data is of comparable quality to 2011 and 2006 Census data and comparable to international benchmarks. Their report is now available.

We have published data quality statements and fact sheets about the quality for each Census variable, including non-response rates and results of data quality investigations, in order to explain the quality of the information to data users.

What happened on Census night?o

DDoS Attacks
On Census night, 9 August 2016, the online form suffered a series of outages due to distributed denial of service (DDoS) attacks. Australians accessing the online form did not cause a system failure, submission rates were within expectations and load capacity.

Hardware Failure
An attempt to restore the system during the fourth DDoS attack led to the failure of one of our supplier’s routers, compounding network issues.

Monitoring Systems
Network performance monitoring systems indicated there was unusual outbound traffic from our systems. It was later determined this was a system monitoring error and there was no unusual outbound traffic from the system.

ASD Report
The Australian Signals Directorate (ASD) reported the incident was a DDoS attack and it did not result in any unauthorised access to, or extraction of, any personal information.

What we did about it

Online Form Closed
At the time, we were unable to determine if the unusual outbound traffic from our systems was malicious or benign. We took decisive action to close the online form to protect the privacy of the Australian public

Pro-privacy Approach
In a statement on 11 August 2016, the Australian Privacy Commissioner (and Acting Australian Information Commissioner) said that our decision to shut down the online form was, in the circumstances, a pro-privacy precaution and was satisfied that personal information was not inappropriately accessed, lost or mishandled.

Online Form Reopened
We reopened the online form to the Australian public, 1 day 18 hours and 44 minutes after we took the decision to close the online form. During this time we implemented protocols to lessen the risk of any further outages.

Sorry Australia
We apologised to the Australian public. Thanks to their overwhelming support and participation, we received a total of 4.9 million online submissions and 3.5 million paper forms - with 63.3% of participants completing their Census form online.

What we're doing

Organisational Transformation
We are undergoing a major transformation at the ABS, recognising that we need to continue delivering high quality statistics including Census data, while taking advantage of new information opportunities, strengthening our partnerships, and driving high performance. We're applying learnings from the Census to enhance our transformation.

Special Adviser to the Prime Minister
The Special Adviser to the Prime Minister on Cyber Security undertook a review of the events surrounding the outage of the online Census form. We accepted and are implementing the recommendations - seven have been completed, final two due to be completed in December 2017.

Australian Senate
The Senate Economics References Committee conducted an inquiry into our preparation, administration and management of the 2016 Census. The Government tabled its response to the findings of the Committee, addressing the recommendations raised in their report.

Australian Federal Police
The Australian Federal Police is investigating the incident to attempt to identify who is responsible for the DDoS attacks.

Will there be a Census in 2021 and into the future?

Absolutely. The law requires it and the ABS is committed to the production of high quality statistics from the Census. We are also committed to continuous improvement in how we do our business, in order to deliver high quality, timely information that Australia needs.

The ABS is transforming its social and people statistics, with the aim of producing data on the economic and social conditions of Australians more frequently and in a timelier manner. The ABS sees significant value in better and more frequent data. Decisions relating to the content and processes for how we run the Census will be considered in this context and made in consultation with Government, stakeholders and the public.

Following the 2016 Census, an independent survey found:

- 92 per cent of people agreed the Census is important for the community
- 93 per cent agreed Census information is necessary for government planning
- 89 per cent agreed the Census is the best way to estimate Australia’s population and its characteristics
- 92 per cent agreed it is important for the community that a Census is conducted.

oSource: Review of the events surrounding the 2016 eCensus: Improving institutional cyber security culture and practices across the Australian government—Alastair MacGibbon, Special Adviser to the Prime Minister on Cyber Security—Department of the Prime Minister and Cabinet—13 October 2016