65% (1975)

71% (1973)

72% (1976)

62% (1973)

76% (1972)

69% (1970)

66% (1977)

62% (1977)

62% (1980)

60% (1981)

54% (1979)

58% (1977)

66% (1974)

56% (1985)

58% (1976)

64% (1984)

64% (1975)

58% (1983)

58% (1977)

60% (1972)