23% (1997)

40% (1992)

50% (1986)

38% (1990)

51% (1992)

46% (1986)

49% (1994)

50% (1988)

54% (1989)

47% (1998)

57% (1990)

39% (1988)

46% (1993)

36% (2000)

37% (1996)

30% (1995)

36% (1995)

22% (1992)

44% (1998)

36% (1986)