54% (1983)

55% (1987)

54% (1977)

42% (1980)

69% (1986)

40% (1987)

58% (1993)

58% (1992)

38% (1981)

57% (1980)

47% (1982)

73% (1989)

52% (1999)

69% (1981)

54% (1991)

52% (1997)

55% (1984)

27% (1996)

31% (1997)

38% (1991)