66% (1976)

78% (1987)

58% (1974)

69% (1979)

81% (1984)

54% (1975)

70% (1978)

63% (1967)

68% (1991)

77% (1959)

69% (1964)

56% (1981)

72% (1961)

74% (1961)

77% (1973)

79% (1962)

78% (1986)

76% (1966)

74% (1983)

51% (1979)