77% (2003)

84% (2005)

71% (1993)

84% (1987)

79% (1993)

77% (1993)

78% (1995)

60% (1969)

73% (1982)

82% (1998)

77% (1985)

79% (1996)

81% (2005)

75% (2005)

76% (2001)

54% (1991)

71% (1962)

74% (1995)

81% (1966)

72% (1978)