62% (1976)

67% (1982)

60% (1978)

65% (1976)

61% (1979)

56% (1976)

57% (1979)

68% (1974)

69% (1975)

61% (1982)

68% (1976)

51% (1981)

64% (1977)

54% (1979)

52% (1983)

62% (1977)

54% (1978)

45% (1981)

45% (1974)

40% (1983)