81% (1979)

82% (1986)

72% (1990)

70% (1988)

62% (1982)

72% (1976)

60% (1979)

70% (1980)

63% (1978)

60% (1979)

70% (1979)

67% (1977)

80% (1982)

60% (1976)

77% (1987)

50% (1974)

66% (1978)

85% (1985)

50% (1989)

63% (1979)