57% (1980)

73% (1979)

74% (1982)

83% (1981)

59% (1991)

52% (1996)

64% (1991)

50% (1979)

58% (1998)

77% (1982)

47% (1994)

50% (1983)

77% (1988)

55% (1999)

57% (1995)

72% (1994)

54% (1989)

69% (1981)

75% (1985)

72% (1989)