67% (1984)

52% (1983)

53% (1986)

57% (1988)

56% (1989)

61% (1981)

49% (1985)

58% (1987)

61% (1984)

65% (1978)

45% (1984)

67% (1988)

61% (1984)

49% (1983)

33% (1984)

58% (1985)

63% (1983)

55% (1987)

71% (1988)

58% (1985)