50% (1976)

63% (1982)

52% (1977)

57% (1979)

58% (1983)

54% (1983)

53% (1984)

53% (1974)

28% (1985)

45% (1979)

44% (1984)

47% (1984)

40% (1976)

36% (1980)

68% (1979)

35% (1985)