72% (1978)

74% (1977)

72% (1974)

69% (1982)

64% (1978)

69% (1982)

61% (1976)

80% (1978)

59% (1980)

63% (1978)

64% (1982)

67% (1980)

61% (1980)

52% (1980)

57% (1978)

59% (1980)

52% (1981)

57% (1971)

48% (1983)

67% (1983)