28% (1988)

48% (1987)

36% (1988)

35% (1992)

37% (1989)

41% (1988)

35% (1993)

45% (1987)

24% (1989)

33% (1990)

41% (1990)

28% (1989)

21% (1989)

34% (1987)

38% (1989)

48% (1989)

42% (1992)

46% (1986)

37% (1991)

27% (1990)