76% (1980)

74% (1985)

76% (1984)

56% (1985)

77% (1982)

69% (1984)

67% (1993)

70% (1986)

70% (1977)

63% (1979)

65% (1978)

58% (1983)

71% (1980)

50% (1984)

60% (1983)

60% (1982)

59% (1987)

50% (1977)

58% (1981)

59% (1974)