27% (1979)

51% (1978)

47% (1989)

45% (1979)

54% (1990)

54% (1987)

58% (1977)

49% (1980)

63% (1977)

50% (1978)

50% (1982)

64% (1978)

50% (1983)

50% (1979)

42% (1978)

60% (1985)

46% (1978)

45% (1980)

53% (1979)

57% (1982)