53% (1983)

55% (1987)

73% (1989)

69% (1986)

54% (1991)

58% (1980)

38% (1981)

54% (1990)

55% (1977)

73% (1993)

39% (1980)

55% (1992)

32% (1991)

40% (1987)

50% (1988)

32% (1997)

74% (1992)

57% (1996)

20% (1980)

27% (1996)