60% (1990)

58% (1989)

61% (1989)

51% (1987)

47% (1985)

50% (1984)

64% (1978)

52% (1989)

49% (1988)

51% (1989)

61% (1985)

36% (1986)

34% (1987)

46% (1988)

56% (1987)

47% (1983)

62% (1988)

51% (1989)

52% (1988)

43% (1987)