80% (1978)

74% (1977)

64% (1978)

72% (1974)

72% (1978)

70% (1983)

72% (1977)

72% (1978)

70% (1982)

63% (1978)

62% (1976)

61% (1980)

61% (1977)

63% (1971)

68% (1983)

56% (1971)

68% (1971)

69% (1984)

57% (1978)

67% (1970)