70% (1981)

63% (1981)

62% (1982)

54% (1989)

48% (1983)

51% (1982)

56% (1979)

43% (1983)

55% (1980)

43% (1989)

58% (1990)

52% (1988)

31% (1980)

51% (1987)

39% (1989)

44% (1987)

33% (1988)

52% (1990)

50% (1990)

54% (1979)