Question: When was the Prime Minister of Australia born who defeated Abbott in 14 September 2015?

Context articles: Australian federal election, 2013
Malcolm Turnbull
Turnbull Government
First Turnbull Ministry
Ben Whiteman
Abbott Government
Tony Abbott
Ömürbek Babanov
Barnaby Joyce
Joe Hockey

A federal election to determine the members of the 44th Parliament of Australia took place on 7 September 2013.
 The centre-right Liberal/National Coalition opposition led by then-Opposition leader Tony Abbott of the Liberal Party of Australia and Coalition partner the National Party of Australia, led by Warren Truss, defeated the incumbent centre-left Labor Party government of Prime Minister Kevin Rudd by a 17-seat 3.6 percentage point two-party swing.
 Labor had been in government since the 2007 election.
 Abbott was sworn in by the Governor-General, Quentin Bryce as Australia's 28th Prime Minister on 18 September 2013 along with the Abbott Ministry and the members of the House of Representatives.
 The 44th Parliament of Australia opened on 12 November 2013, which is taken to be the commencement of the term of members of the House of Representatives.
 The new senators were sworn in by the next Governor-General Peter Cosgrove on 7 July 2014, with their six-year terms commencing on 1 July.
Malcolm Bligh Turnbull (born 24 October 1954) is the 29th and current Prime Minister of Australia.
 He first served as parliamentary leader of the Liberal Party and as opposition leader from 2008 to 2009, and became parliamentary leader and Prime Minister after defeating Tony Abbott at the 2015 Liberal leadership spill.
 The Turnbull Government was re-elected at the 2016 federal election, but with only a one-seat majority.
The Turnbull Government is the federal executive government of Australia, led by the 29th Prime Minister of Australia, Malcolm Turnbull.
 The government is made of members of the Liberal-National Coalition.
 The prime ministership of Malcolm Turnbull commenced on 15 September 2015, when he was sworn in by the Governor-General of Australia.
 The Turnbull Government succeeded the Abbott Government, which was elected at the 2013 federal election.
 Turnbull took office by challenging the incumbent Liberal leader Tony Abbott in an internal leadership ballot.
 Warren Truss, the leader of the Nationals continued as Deputy Prime Minister, until he retired in 2016 and was replaced by Barnaby Joyce.
The First Turnbull Ministry (Liberal–National Coalition) was the 70th ministry of the Government of Australia, led by Prime Minister Malcolm Turnbull.
 It succeeded the Abbott Ministry after a leadership spill that took place on 14 September 2015 ended Prime Minister Tony Abbott's leadership of the Liberal Party of Australia.
 On 15 September, the National Party confirmed, after successful negotiations, that it would continue a coalition agreement with the Liberal Party, guaranteeing the Turnbull Government a majority in the Australian House of Representatives.
Bernard "Ben" Denzil Whiteman (born 20 August 1954) is a Curaçaoan politician.
 He was Prime Minister of Curaçao from September 2015 to December 2016.
 He succeeded Ivar Asjes after Asjes resigned after he lost confidence of his own party.
 Whiteman was sworn in as Prime Minister on 1 September 2015.
 He also was the Minister of Public Health, Environment and Nature since 31 December 2012 in the Asjes-Cabinet and the Hodge-Cabinet before taking the post, retaining the position after becoming prime minister.
The Abbott Government was the federal executive government of Australia led by Prime Minister Tony Abbott.
 The Government was made up of members of the Liberal–National Coalition.
 The Leader of the Nationals, Warren Truss, served as Deputy Prime Minister.
 Following the 2013 Australian federal election on 7 September, the Coalition defeated the second Rudd Government, ending six years of Labor Government.
 The Abbott Government was sworn into office on 18 September 2013.
 Less than two years later on 14 September 2015, Malcolm Turnbull defeated Abbott in a leadership ballot, 54 votes to 44.
Anthony John Abbott (born 4 November 1957) is an Australian politician who was the 28th Prime Minister of Australia, from 18 September 2013 to 15 September 2015.
 Abbott was leader of the Liberal Party of Australia from 2009 to 2015, and has been a member of parliament for Warringah since 1994.
Ömürbek Toktogulovich Babanov (Kyrgyz: Өмүрбек Токтогулович Бабанов; born 15 January 1970) is a Kyrgyz politician who was Prime Minister of Kyrgyzstan from 1 December 2011 to 1 September 2012.
 Before his appointment as Prime Minister, he was Deputy Prime Minister in the Government of Almazbek Atambayev.
 He was also acting Prime Minister from 23 September 2011 until 14 November 2011, as the Prime Minister Atambayev was a candidate in the presidential election.
 He again became acting Prime Minister on 1 December 2011 when Atambayev took office as President.
 He was confirmed by Parliament on 23 December 2011.
 On 1 September 2012 Babanov resigned as Prime Minister.
Barnaby Thomas Gerard Joyce (born 17 April 1967) is an Australian politician who has served as the Deputy Prime Minister of Australia since 18 February 2016, as the Leader of the National Party of Australia since 11 February 2016, and as the Minister for Agriculture and Water Resources since 21 September 2015.
 He was sworn in as Minister for Agriculture in the Abbott Government on 18 September 2013.
 Water Resources was added to his portfolio on 21 September 2015 in the Turnbull Government.
Joseph Benedict "Joe" Hockey (born 2 August 1965) is the current Ambassador of Australia to the United States.
 He is a former Australian politician, the Member of Parliament for North Sydney from 1996 until 2015.
 He was the Treasurer of Australia in the Abbott Government from 18 September 2013 until September 2015 when he resigned from Cabinet, having refused an alternative offer from the incoming Prime Minister, Malcolm Turnbull.
 He previously served as the Minister for Human Services and Minister for Employment and Workplace Relations in the Howard Government.