76% (1979)

57% (1987)

65% (1980)

64% (1983)

77% (1981)

73% (1984)

66% (1985)

67% (1985)

58% (1975)

73% (1983)

73% (1977)

74% (1984)

74% (1976)

60% (1989)

66% (1978)

65% (1988)

71% (1986)

68% (1990)

100% (1979)

0% (1974)