66% (1985)

71% (1987)

71% (1989)

57% (1981)

64% (1982)

67% (1993)

73% (1987)

68% (1983)

60% (1976)

69% (1985)

67% (1986)

68% (1980)

63% (1990)

77% (1986)

61% (1988)

68% (1986)

80% (1984)

55% (1994)

57% (1993)

74% (1991)