65% (1983)

74% (1984)

60% (1975)

58% (1981)

69% (1979)

80% (1989)

68% (1987)

67% (1976)

60% (1982)

78% (1987)

70% (1981)

50% (1986)

67% (1983)

70% (1980)

80% (1978)