68% (1984)

62% (1988)

56% (1975)

50% (1976)

60% (1968)

33% (1975)

55% (1974)

71% (1988)

69% (1986)

73% (1986)

65% (1985)

72% (1984)

40% (1973)

63% (1971)

64% (1980)

65% (1980)

0% (1970)

0% (1971)

0% (1978)

0% (1961)