Question: When did the politician who represented the electoral district in Sydney's West resign from his political party?
Related documents: [0]  [DOC] 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. [END] 
[1]  [DOC] 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. [END] 
Answer: 
2015
2015