73% (1986)

56% (1975)

72% (1984)

68% (1983)

65% (1987)

68% (1984)

69% (1986)

65% (1985)

55% (1974)

0% (1977)

65% (1980)

64% (1980)

68% (1976)

63% (1971)

0% (1968)

62% (1988)

0% (1966)

59% (1971)

54% (1973)

71% (1988)