50% (1985)

58% (1986)

50% (1980)

39% (1986)

23% (1986)

47% (1970)

44% (1979)

49% (1982)

49% (1990)

10% (1977)

20% (1992)

39% (1987)

38% (1985)

43% (1983)

28% (1984)

55% (1987)

35% (1980)

48% (1987)

52% (1992)

45% (1994)