55% (1999)

62% (2001)

48% (2004)

69% (1996)

58% (2007)

70% (2007)

71% (1994)

64% (1995)

64% (1985)

59% (2002)

72% (1992)

64% (1992)

60% (1987)

65% (2008)

61% (1997)

65% (1987)

56% (2010)

57% (1991)

73% (1987)

61% (2015)