67% (1971)

62% (1964)

61% (1974)

62% (1962)

67% (1960)

62% (1970)

58% (1971)

64% (1966)

63% (1962)

71% (1961)

59% (1970)

66% (1968)

54% (1972)

66% (1958)

65% (1962)

56% (1965)

67% (1963)

60% (1979)

72% (1960)

65% (1971)