55% (1983)

69% (1986)

55% (1987)

57% (1980)

74% (1992)

39% (1980)

50% (1982)

31% (1997)

47% (1982)

54% (1977)

52% (1997)

57% (1996)

58% (1992)

73% (1989)

54% (1991)

45% (1981)

50% (1988)

30% (1991)

27% (1996)

52% (1999)