71% (1981)

68% (1980)

76% (1967)

57% (1980)

66% (1981)

71% (1968)

74% (1968)

58% (1981)

69% (1970)

66% (1971)

56% (1980)

57% (1970)

61% (1979)

62% (1974)

63% (1982)

59% (1977)

76% (1970)

64% (1970)

59% (1973)

48% (1979)