54% (1983)

69% (1986)

54% (1991)

72% (1993)

55% (1987)

58% (1992)

54% (1977)

57% (1980)

73% (1989)

70% (1981)

42% (1980)

31% (1997)

54% (1990)

20% (1980)

52% (1999)

52% (1984)

74% (1992)

47% (1982)

27% (1996)

50% (1988)