50% (1989)

20% (1992)

35% (1987)

47% (1995)

20% (1998)

47% (1983)

57% (1989)

35% (1998)

20% (1988)

20% (1983)

65% (1999)

30% (1988)

20% (1993)

40% (1996)

20% (1991)

20% (1988)

20% (1993)

30% (1999)

20% (2003)

40% (1986)