48% (1983)

45% (1985)

42% (1984)

31% (1985)

69% (1986)

75% (1986)

68% (1980)

73% (1981)

70% (1979)

74% (1974)

64% (1983)

76% (1986)

69% (1985)

56% (1969)

72% (1980)

61% (1980)

41% (1985)

69% (1988)

65% (1977)

64% (1984)