66% (1976)

81% (1984)

70% (1979)

78% (1987)

59% (1974)

55% (1975)

72% (1961)

77% (1959)

72% (1966)

76% (1966)

79% (1962)

70% (1978)

69% (1991)

63% (1967)

74% (1961)

77% (1973)

77% (1986)

54% (1981)

68% (1963)

74% (1967)