In addition, there are two non-geographical districts. In District XI, 3 members are chosen by proportional representation to represent Croatian citizens residing abroad (this district is commonly referred to as the "diaspora electorate"). Although all people living outside Croatia are eligible to vote for this list, the majority of voters who turnout for this list traditionally consists of Croats of Bosnia and Herzegovina, the majority of whom hold dual Croatian and Bosnian citizenships. In District XII an additional 8 members are elected to represent the 22 ethnic minorities in Croatia which are legally recognized as such in the Croatian Constitution, with 3 of these seats reserved for the Serbian minority. Since the seats are allocated according to the proportion of votes received in each district, parties usually nominate senior party officials on top of their lists in districts where they have traditionally enjoyed good levels of support, to ensure that the party's most prominent members win parliamentary seats. All candidates are elected to four-year terms. However, many MPs who are members of post-election ruling coalitions often get appointed to various ministerial and government positions while others serve as city mayors or directors of various government agencies. In such cases they are required by law to put their parliamentary mandate on hiatus for the duration of their other term in office and their seats are then taken by party-appointed deputy MPs. The Constitution and consequently the electoral law has been changed in June 2010 to give District XI 3 fixed seats. In the past, the number of seats given to the district was proportional to the number of voters taking part. In the last elections in 2007, this resulted in 5 seats being allocated to the district. In December 2010, the Constitutional Court of Croatia decided to inform the Parliament of a necessity to update the electoral unit definitions according to current population data, in accordance with the provisions of the 1999 Law on electoral units. The main actors of the election remain entrenched from the previous election cycle – the right-centre block led by the Croatian Democratic Union (HDZ), and the left-centre block led by the Social Democratic Party of Croatia. The main supporting party of the right-centre block is the Croatian Peasant Party. In 2011, President of Croatian Peasant Party announced that his party would not be part of center right coalition with HDZ. The main supporting party in the left-centre block is the Croatian People's Party - Liberal Democrats. The left-centre block officially joined an electoral coalition called Alliance for Change in 2010, renamed to Kukuriku coalition in 2011. In 2010, the Croatian Social Liberal Party lost representation in Parliament because of an internal split between Ivan Čehok, Đurđa Adlešič and others with newly elected party leader Darinko Kosor.