78% (1962)

78% (1969)

72% (1960)

66% (1951)

66% (1959)

56% (1965)

47% (1960)

59% (1969)

50% (1971)

64% (1961)

66% (1956)

62% (1968)

70% (1956)

40% (1973)

60% (1963)

58% (1953)

70% (1966)

63% (1957)

64% (1958)

37% (1971)