73% (1973)

68% (1976)

64% (1976)

55% (1980)

47% (1983)

58% (1982)

53% (1978)

51% (1978)

47% (1978)

48% (1977)

48% (1983)

48% (1982)

43% (1982)

42% (1981)

27% (1986)

48% (1983)

33% (1979)

50% (1973)

41% (1967)

32% (1983)