52% (1993)

51% (1991)

55% (1989)

57% (1988)

66% (1994)

54% (1997)

58% (1991)

51% (2007)

56% (1988)

64% (1986)

25% (1985)

45% (2011)

43% (2010)

44% (2005)

51% (2004)

45% (2009)

43% (1999)

50% (2006)

50% (1995)