57% (1986)

39% (1987)

59% (1984)

63% (1981)

68% (1990)

46% (1986)

61% (1986)

64% (1982)

69% (1986)

53% (1991)

53% (1983)

61% (1983)

59% (1983)

54% (1986)

66% (1984)

45% (1991)

61% (1992)

50% (1985)

53% (1989)

69% (1984)