68% (1978)

56% (1973)

52% (1980)

33% (1984)

0% (1980)

53% (1987)

20% (1980)

57% (1976)

58% (1987)

0% (1975)

60% (1976)

62% (1988)

62% (1987)

60% (1977)

35% (1989)

0% (1975)

0% (1980)

50% (1986)

64% (1987)

58% (1983)