80% (1978)

74% (1977)

72% (1974)

70% (1983)

71% (1978)

63% (1978)

56% (1971)

61% (1980)

69% (1982)

71% (1977)

72% (1978)

67% (1983)

69% (1982)

68% (1984)

60% (1977)

63% (1978)

64% (1971)

58% (1978)

59% (1970)

67% (1970)