88% (1994)

86% (1999)

80% (1995)

67% (2011)

68% (2004)

76% (1992)

73% (2007)

81% (2010)

78% (1990)

56% (1996)

74% (1989)

66% (2000)

79% (2004)

64% (2010)

56% (2003)

70% (1993)

58% (2005)

64% (2002)

67% (2007)

73% (1995)