• The 2013 federal election was held on Saturday 7 September 2013.
• In the 44th Parliament, the first meeting of the House of Representatives was held on Tuesday 12 November 2013.
• The certificate containing the ascertained populations, calculations and adjustments was published in Gazette No. C2014G01876 on Monday 17 November 2014.

• The 2010 federal election was held on Saturday 21 August 2010.
• In the 43rd Parliament, the first meeting of the House of Representatives was held on Tuesday 28 September 2010.
• The ertificate containing the ascertained populations, calculations and adjustments was published in Gazette No. S150 on Friday 30 September 2011.

• The 2007 federal election was held on Saturday 24 November 2007.
• In the 42nd Parliament, the first meeting of the House of Representatives was held on Tuesday 12 February 2008.
• The determination of the number of members was published in Gazette No. S28 on Tuesday 17 February 2009.
• The certificate containing the ascertained populations, calculations and adjustments was published on page 524 in Gazette No. GN8 on Wednesday 4 March 2009.

• The 2004 federal election was held on Saturday 9 October 2004.
• In the 41st Parliament, the first meeting of the House of Representatives was held on Tuesday 16 November 2004.
• The certificate containing the determination of the number of members, ascertained populations, calculations and adjustments was published in Gazette No. S201 on Thursday 17 November 2005.

• The 2001 federal election was held on Saturday 10 November 2001.
• In the 40th Parliament, the first meeting of the House of Representatives was held on Tuesday 12 February 2002.
• The certificate containing the determination of the number of members and ascertained populations was published in Gazette No. S45 on Wednesday 26 February 2003.

• The 1998 federal election was held on Saturday 3 October 1998.
• In the 39th Parliament, the first meeting of the House of Representatives was held on Tuesday 10 November 1998.
• The certificate containing the determination of the number of members and ascertained populations was published in Gazette No. S605 on Friday 10 December 1999.

• The 1996 federal election was held on Saturday 2 March 1996.
• In the 38th Parliament, the first meeting of the House of Representatives was held on Tuesday 30 April 1996.
• The certificate containing the determination of the number of members and ascertained populations was published in Gazette No. S76 on Monday 3 March 1997.

• The 1993 federal election was held on Saturday 13 March 1993.
• In the 37th Parliament, the first meeting of the House of Representatives was held on Tuesday 4 May 1993.
• The certificate containing the determination of the number of members and ascertained populations was published in Gazette No. S77 on Friday 4 March 1994.

• The 1990 federal election was held on Saturday 24 March 1990.
• In the 36th Parliament, the first meeting of the House of Representatives was held on Tuesday 8 May 1990.
• The certificate containing the determination of the number of members and ascertained populations was published in Gazette No. S58 on Friday 1 March 1991.

• The 1987 federal election was held on Saturday 11 July 1987.
• In the 35th Parliament, the first meeting of the House of Representatives was held on Monday 14 September 1987.
• The certificate containing the determination of the number of members for the states and ascertained populations for the states was published on page 2 in Gazette No. S194 on Friday 1 July 1988.

• The 1984 federal election was held on Saturday 1 December 1984.
• In the 34th Parliament, the first meeting of the House of Representatives was held on Thursday 21 February 1985.
• The certificate containing the determination of the number of members for the states and ascertained populations for the states was published in Gazette No. S59 on Tuesday 18 February 1986.

Paragraph 46(1A)(a) of the Electoral Act specifies:

The reference day is the first day after the end of the 12 month period following for the first meeting day of the House of Representatives.

The first meeting day, also known as the first sitting day, is in Votes and Proceedings, the official record of the proceedings of the House of Representatives.

On the reference day, the Electoral Commissioner is required to ascertain the number of people of:

• the Commonwealth – pursuant to section 45 of the Electoral Act, the number of the people of the Commonwealth does not include the people of the Territories,
• each of the States,
• the Australian Capital Territory, including Jervis Bay,
• the Northern Territory,
• Norfolk Island,
• the Territory of Cocos (Keeling) Islands,
• the Territory of Christmas Island, and
• each of the other Territories – Australian Antarctic Territory, Territory of Heard Island and McDonald Islands, Coral Sea Islands Territory and the Territory of Ashmore and Cartier Islands.

This ascertainment uses statistics supplied by the Australian Statistician.   These statistics must be compiled and published in a regular series under the Census and Statistics Act 1905, with the specific statistics supplied to be those most recently published before the reference day.

The ABS regularly publishes population data.

Calculating how many members of the House of Representatives each state and territory is entitled uses a population quota.

Dividing the ascertained number of people for the Commonwealth by twice the number of Senators for the states gives the population quota.

• Each state has 12 Senators
• The total number of Senators for the states is 72
• Twice the number of Senators for the states is 144

This step applies to New South Wales, Victoria, Queensland, Western Australia, South Australia and Tasmania.

To calculate the number of members of the House of Representatives for a state, the ascertained number of people of the state is divided by the population quota, and the result rounded to the nearest whole number.

Rounding up or down?

In calculating the number of members of the House of Representatives for a state, if the remainder is more than 0.5, the figure for the number of members is rounded up. If the remainder is less than or equal to 0.5, the figure is rounded down (i.e. 32.5 = 32 members, and 32.52 = 33 members).

Tasmania’s entitlement to five members

Section 24 of the Commonwealth of Australia Constitution Act specifies the requirements for the composition of the House of Representatives, requiring that ‘... five members at least shall be chosen in each Original State’. Original States are defined in section 6 as meaning ‘... such States are parts of the Commonwealth at its establishment’.

As Tasmania is an Original State, it is guaranteed a minimum of five members of the House of Representatives.

This step applies to the ACT, the Northern Territory, Christmas Island, Cocos (Keeling) Islands, Norfolk Island, Australian Antarctic Territory, Territory of Heard Island and McDonald Islands, Coral Sea Islands Territory and the Territory of Ashmore and Cartier Islands.

To calculate the number of members of the House of Representatives for a territory, the ascertained number of people of the territory is divided by the population quota, and the result rounded to the nearest whole number.

Rounding up or down?

In calculating the number of members of the House of Representatives for a territory, if the remainder is more than 0.5, the figure for the number of members is rounded up. If the remainder is less than or equal to 0.5, the figure is rounded down (i.e. 2.5 = 2 members, and 2.52 = 3 members).

Minimum number of members for the ACT and Northern Territory

Sub-section 48(2B) of the Electoral Act requires that at least one member of the House of Representatives shall be chosen in the Northern Territory and the ACT at a general election.

• Section 122 of the Commonwealth of Australia Constitution Act allows the Government to make laws for territories and provides that the Government ‘... may allow the representation of such territory in either House of the Parliament to the extent on the terms which it thinks fit’.

When Norfolk Island is not entitled to any members of the House of Representatives, the Electoral Act requires that the population of Norfolk Island is added to that of the ACT and the ACT’s entitlement to members of the House of Representatives is recalculated.

Sub-section 48(2BA) of the Electoral Act provides for the following to occur:

• the ascertainment of the ACT’s population is deemed to have never been made,
• the number of the people of the ACT will be re-ascertained, by adding the number of the people of Norfolk Island to the number of people for the ACT, and
• the Electoral Commissioner will use the newly ascertained number of people of the ACT to determine the number of members of the House of Representatives to be chosen in the ACT.

The rounding rules continue to apply, as does the requirement for a minimum number of members for the ACT.

Under section 56A of the Electoral Act, until such time as the Territory of Cocos (Keeling) Islands or the Territory of Christmas Island is entitled to a member of the House of Representatives, each Territory is to be included in the same electoral division in the Northern Territory.

Sub-section 48(2C) of the Electoral Act provides for the following to occur:

• the ascertainment of the Northern Territory’s population is deemed to have never been made,
• the number of the people of the Northern Territory will be re-ascertained, with the number of people of the Territory of Cocos (Keeling) Islands and the Territory of Christmas Island being added to that of the Northern Territory, and
• the Electoral Commissioner will use the newly ascertained number of people of the Northern Territory to determine the number of members of the House of Representatives to be chosen in the Northern Territory at a general election.

The rounding rules continue to apply, as does the requirement for a minimum number of members for the Northern Territory.

Where the number of members of the House of Representatives to which the ACT or Northern Territory is entitled is equal to a whole number (known as the ‘relevant whole number’) and a remainder that is less than or equal to one-half of the population quota, an additional review process takes place.

This review process may result in altering the ascertained population, which in turn may result in the number of members to be chosen increasing.

Sub-section 48(2E) of the Electoral Act provides for the adjusted ascertained population to be altered if the following holds true:

The standard error of the Australian Statistician’s estimate of the net undercount is available in Census publications.

When the calculation holds true

Sub-section 48(2F) of the Electoral Act, provides for the following to occur:

• the ascertained population of the relevant territory, both the original and adjusted, are taken to never have been made,
• the number of the people of the relevant territory is increased by a number equal to twice the standard error of the estimated net undercount for the relevant territory,
• the Electoral Commissioner will use the newly ascertained number of people of the relevant territory to determine the number of members of the House of Representatives to be chosen in the relevant territory at a general election.

The rounding rules continue to apply, as does the requirement for a minimum number of members for the ACT and the Northern Territory.

When the calculation does not hold true

The number of members to be chosen in the relevant territory at a general election is:

• for the ACT – the number calculated at Step 6
• for the Northern Territory – the number calculated at Step 7.

Following ascertainment of the populations and determining the number of members of the House of Representatives for each state and territory, the Electoral Commissioner is required to:

• provide a certificate to the responsible Minister, and
• publish a copy of the certificate in the Gazette within one month of the reference day.

The Minister is required to lay a copy of this certificate before each House of Parliament within five sitting days of receipt of the certificate.

Contents of the certificate

The certificate is required to contain:

• the populations ascertained by the Electoral Commissioner of the Commonwealth, each of the states and each of the territories;
• the number of members of the House of Representatives determined by the Electoral Commissioner;
• any adjustments made to the statistics supplied by the Australian Statistician undertaken in order to ascertain the populations; and
• any calculations or adjustments in determining the number of members of the House of Representatives to be chosen at a general election.

Possible outcomes from the calculating the representation entitlements of states and territories

The possible outcomes from the process are:

• no change to the number of members – no further action is taken;
• change in the number of members – a redistribution of the affected state or territory will be triggered; or
• a territory’s entitlement increases or decreases to one member – the change applies from when the number of members is determined.