73% (1977)

80% (1978)

71% (1974)

72% (1978)

63% (1978)

70% (1983)

56% (1971)

69% (1982)

61% (1980)

68% (1984)

71% (1977)

72% (1978)

60% (1977)

67% (1983)

69% (1982)

67% (1970)

52% (1980)

61% (1976)

55% (1980)

57% (1978)