69% (1981)

63% (1981)

62% (1982)

55% (1980)

43% (1983)

50% (1982)

42% (1989)

55% (1989)

47% (1983)

54% (1985)

54% (1979)

51% (1987)

51% (1988)

59% (1990)

48% (1988)

49% (1984)

54% (1979)

33% (1988)

46% (1991)

43% (1992)