63% (1981)

43% (1983)

55% (1980)

69% (1981)

62% (1982)

54% (1989)

50% (1990)

48% (1983)

44% (1987)

58% (1990)

43% (1989)

33% (1988)

52% (1990)

52% (1988)

55% (1985)

54% (1979)

31% (1980)

51% (1982)

51% (1987)

28% (1992)