68% (1983)

73% (1984)

72% (1986)

62% (1980)

66% (1986)

73% (1994)

63% (1978)

71% (1985)

67% (1980)

63% (1984)

50% (1979)

63% (1983)

70% (1996)

70% (1986)

50% (1981)

50% (1979)

42% (1983)