77% (1967)

71% (1981)

68% (1970)

57% (1980)

67% (1980)

66% (1981)

71% (1968)

74% (1968)

66% (1971)

76% (1970)

64% (1970)

61% (1974)

57% (1981)

59% (1977)

63% (1982)

60% (1979)

57% (1972)

56% (1980)

57% (1970)

62% (1974)