70% (1983)

35% (2010)

20% (1988)

58% (2010)

80% (2007)

61% (1989)

68% (2006)

64% (2012)

29% (2011)

36% (2008)

35% (2009)

20% (2008)

35% (2009)

40% (2007)

55% (1998)

50% (2000)

35% (2005)

40% (2009)