54% (1983)

55% (1987)

54% (1977)

69% (1986)

57% (1980)

54% (1991)

47% (1982)

73% (1989)

58% (1992)

72% (1993)

52% (1999)

74% (1992)

69% (1981)

58% (1993)

31% (1997)

80% (1997)

40% (1987)

50% (1988)

70% (1989)

42% (1980)