35% (1988)

49% (1987)

27% (1988)

42% (1990)

46% (1987)

40% (1991)

36% (1990)

34% (1990)

22% (1989)

37% (1989)

29% (1988)

46% (1988)

40% (1990)

38% (1989)

38% (1992)

20% (1991)

36% (1992)

46% (1986)

38% (1989)

48% (1989)