59% (1972)

61% (1974)

67% (1971)

64% (1962)

59% (1970)

62% (1970)

56% (1968)

61% (1960)

63% (1962)

60% (1966)

60% (1966)

62% (1971)

58% (1971)

61% (1966)

75% (1972)

64% (1966)

67% (1963)

56% (1965)

58% (1959)

75% (1961)