64% (1986)

50% (1988)

35% (1988)

30% (1987)

51% (1984)

28% (1985)

72% (1987)

45% (1979)

62% (1977)

50% (1980)

58% (1985)

58% (1986)

43% (1987)

71% (1988)

52% (1988)

45% (1985)

52% (1985)

70% (1986)

52% (1984)

42% (1987)