49% (1987)

27% (1988)

45% (1990)

34% (1990)

35% (1988)

46% (1988)

37% (1989)

38% (1992)

40% (1988)

46% (1987)

38% (1989)

36% (1992)

40% (1991)

42% (1990)

36% (1990)

63% (1989)

34% (1987)

32% (1990)

50% (1991)

43% (1993)