55% (1983)

57% (1980)

69% (1986)

74% (1992)

55% (1987)

27% (1996)

39% (1980)

73% (1989)

50% (1982)

31% (1997)

47% (1982)

52% (1997)

54% (1977)

40% (1987)

58% (1992)

69% (1981)

50% (1988)

73% (1993)

45% (1981)

57% (1996)