55% (1980)

63% (1981)

69% (1981)

42% (1983)

62% (1982)

57% (1990)

53% (1989)

43% (1992)

51% (1982)

48% (1983)

52% (1979)

52% (1988)

51% (1987)

43% (1989)

50% (1990)

46% (1991)

31% (1980)

48% (1988)

57% (1979)

39% (1989)