Question: When did the politician who represented the electoral district in Sydney's West resign from his political party?

full_context: Document 1: Leader of the Opposition (Singapore): The Leader of the Opposition of Singapore is usually the leader of the second largest political party represented in the Parliament of Singapore. During the 1955 Legislative Assembly election, the late Lee Kuan Yew was the "de facto" Leader of the Opposition, as the People's Action Party was then the second largest political party represented in the Legislative Assembly.
Document 2: Stuart Ayres: Stuart Laurence Ayres (born 24 November 1980), an Australian politician, is the New South Wales Minister for Sport since April 2014, the Minister for WestConnex and the Minister for Western Sydney since January 2017 in the Berejiklian government. Ayres is a member of the New South Wales Legislative Assembly since 19 June 2010, representing the electorate of Penrith as a member of the Liberal Party of Australia. Ayres has previously served as the Minister for Trade, Tourism and Major Events between 2015 and 2017; and the Minister for Police and Emergency Services during 2014 and 2015; the Minister Assisting the Premier on Western Sydney between 2013 and 2015; and the Minister for Fair Trading between 2011 and 2014.
Document 3: New South Wales state election, 2019: The next New South Wales state election is scheduled to be held on Saturday 23 March 2019 to elect the 58th Parliament of New South Wales, including all 93 seats in the New South Wales Legislative Assembly and 21 of the 42 seats in the New South Wales Legislative Council. The eight-year two-term incumbent Liberal/National Coalition government, currently led by Premier Gladys Berejiklian, will attempt to win a third four-year term and will be challenged by the Labor opposition, currently led by Opposition Leader Luke Foley.
Document 4: Electoral district of Goulburn: Goulburn is an electoral district of the Legislative Assembly in the Australian state of New South Wales. It is represented by Pru Goward of the Liberal Party of Australia.
Document 5: Fred Nile: Frederick John "Fred" Nile ED MLC (born 15 September 1934) is an Australian politician and ordained Christian minister. Nile has been a member of the New South Wales Legislative Council since 1981, except for a period in 2004 when he resigned to unsuccessfully contest the Australian Senate at the 2004 federal election. Nile was re-elected at the March 2007 state election and is currently Assistant President of the Legislative Council. He is the longest-serving member of the New South Wales parliament. In November 2009 he stated his decision to retire in 2015, but later announced his decision to accept the Christian Democratic Party (CDP) nomination for the NSW Legislative Council at the New South Wales State Election on 28 March 2015.
Document 6: Wes Fang: Wesley (Wes) Joseph Fang is an Australian politician. He has been a NSW Nationals member of the New South Wales Legislative Council since 9 August 2017, when he filled a casual vacancy caused by the resignation of Duncan Gay. Fang has Singaporean heritage and is the first Asian-Australian to represent the Nationals in the New South Wales Parliament. Fang holds a degree in aviation from the University of New South Wales and was formerly a pilot with the Australian Army and Telstra Child Flight, a director of the Wagga Wagga Business Chamber and founded the Wagga Ratepayers' Community.
Document 7: Electoral district of Sydney-Lang: Sydney-Lang was a former electoral district of the Legislative Assembly in the Australian state of New South Wales, created in 1894 from part of the electoral district of West Sydney in inner Sydney and named after Presbyterian clergyman, writer, politician and activist John Dunmore Lang. It was west of George Street, generally south of Margaret Street, north of Hay Street and east of Darling Harbour. It was abolished in 1904 and absorbed into Darling Harbour.
Document 8: Opposition (Australia): In Australian parliamentary practice, the Opposition or Official Opposition is usually the official title of the second largest party or coalition of parties in the Australian House of Representatives with its leader being given the title "Leader of the Opposition". The Opposition serves the same function as the official opposition in other Commonwealth of Nations monarchies that follow the Westminster conventions and practices. It is seen as the alternative government and the existing administration's main opponent in the Australian Parliament and at a general election. By convention, the Opposition Leader in the federal Parliament comes from the House of Representatives, as does the deputy, although the Government and Opposition may also both have leaders in the Senate. The Opposition is sometimes styled as "Her Majesty's Loyal Opposition" to show that, although the group may be against the sitting government, it remains loyal to the Crown (the embodiment of the Australian state), and thus to Australia.
Document 9: Tanya Plibersek: Tanya Joan Plibersek (born 2 December 1969) is an Australian politician who has been the Member of Parliament for Sydney since 1998, and the deputy leader of the opposition and deputy leader of the Labor Party since 2013.
Document 10: Michael Daley: Michael John Daley (born 1 November 1965), an Australian politician, is a member of the New South Wales Legislative Assembly representing Maroubra for the Australian Labor Party since 2005. He is currently the Deputy Leader of the Opposition, Shadow Minister for Planning and Infrastructure, Shadow Minister for Gaming and Racing and Manager of Opposition Business.
Document 11: Division of East Sydney: Australian Electoral Division in New South Wales. The division was created in 1900 and was one of the original 75 divisions contested at the first federal election. It was abolished in 1969. It was named for the suburb of East Sydney. It was located in the inner eastern suburbs of Sydney, including Darlinghurst, Paddington, Redfern, Surry Hills and Waverley. After 1910 East Sydney was usually a safe seat for the Australian Labor Party. In the 1930s it was a stronghold of Lang Labor. Its most prominent members were Sir George Reid, who was Prime Minister of Australia in 1904-05, and Eddie Ward, a long-serving Labor member and Cabinet minister.
Document 12: Electoral district of Sydney-Denison: Sydney-Denison was an electoral district of the Legislative Assembly in the Australian state of New South Wales, created in 1894 from part of the electoral district of West Sydney in the Ultimo area and named after Governor Denison. It was abolished in 1904 and absorbed into the electoral district of Pyrmont.
Document 13: Electoral district of Auburn: Auburn is an electoral district of the Legislative Assembly of the Australian state of New South Wales in Sydney's West. It is currently represented by Luke Foley, the leader of the Australian Labor Party.
Document 14: Luke Foley: Luke Aquinas Foley (born 27 July 1970) is an Australian politician who serves as the Leader of the Opposition in the Parliament of New South Wales and as parliamentary leader of the New South Wales branch of the Australian Labor Party. Foley was a member of the New South Wales Legislative Council since 19 June 2010 until his resignation to contest the Legislative Assembly seat of Auburn at the 2015 New South Wales election.
Document 15: Chris Minns: Christopher John Minns (born 17 September 1979) is an Australian politician who was elected to the New South Wales Legislative Assembly as the member for Kogarah for the Australian Labor Party at the 2015 New South Wales state election. He is currently the opposition spokesman for Water and head of the opposition's waste watch committee.
ground_truth: 2015