71% (1993)

77% (2003)

84% (1987)

78% (1995)

78% (1994)

84% (2005)

79% (1993)

74% (1995)

71% (1962)

80% (1966)

82% (1998)

78% (1970)

30% (1998)

76% (2001)

81% (2005)

77% (1993)

76% (1966)

79% (1996)

76% (1982)

73% (1982)