67% (1976)

81% (1984)

77% (1973)

59% (1974)

70% (1979)

77% (1986)

70% (1978)

78% (1959)

75% (1967)

78% (1987)

54% (1975)

69% (1991)

79% (1962)

63% (1967)

74% (1983)

55% (1981)

72% (1961)

73% (1966)

74% (1961)

76% (1966)