72% (1988)

59% (1986)

59% (1980)

67% (1980)

63% (1974)

61% (1973)

62% (1987)

62% (1986)

64% (1977)

48% (1986)

59% (1986)

64% (1980)

60% (1978)

48% (1979)

62% (1974)

56% (1979)

63% (1972)

33% (1975)

79% (1981)

68% (1976)