63% (1967)

78% (1973)

72% (1977)

69% (1975)

76% (1962)

77% (1969)

73% (1980)

71% (1981)

74% (1968)

69% (1971)

80% (1959)

71% (1970)

71% (1979)

66% (1969)

71% (1976)

72% (1970)

72% (1964)

72% (1962)

71% (1968)

65% (1961)