68% (1973)

78% (1987)

79% (1964)

67% (1976)

63% (1982)

63% (1974)

73% (1975)

68% (1985)

62% (1987)

74% (1995)

77% (1986)

77% (1992)

64% (1978)

67% (1986)

67% (1997)

73% (1984)

73% (1994)

72% (1990)

71% (1984)

66% (1954)