72% (1988)

69% (1981)

59% (1986)

67% (1980)

59% (1980)

61% (1973)

60% (1978)

56% (1979)

63% (1974)

48% (1979)

65% (1986)

62% (1974)

75% (1993)

79% (1981)

63% (1972)

59% (1982)

72% (1981)

68% (1976)

70% (1979)

64% (1977)