49% (1987)

27% (1988)

42% (1992)

46% (1987)

37% (1989)

34% (1990)

36% (1988)

43% (1993)

38% (1989)

41% (1990)

40% (1991)

36% (1990)

20% (1991)

45% (1990)

36% (1992)

33% (1989)

38% (1992)

47% (1989)

50% (1991)

46% (1988)