53% (1981)

70% (1979)

72% (1990)

52% (1989)

62% (1983)

67% (1987)

60% (1979)

70% (1986)

60% (1980)

82% (1986)

67% (1981)

85% (1985)

60% (1976)

70% (1975)

70% (1988)

63% (1986)

63% (1973)

60% (1978)

78% (1976)

72% (1976)