20% (1983)

71% (1998)

20% (1997)

20% (1996)

20% (2000)

20% (1992)

47% (1983)

20% (1998)

20% (1988)

57% (1989)

20% (1992)

20% (1987)

20% (2001)

20% (1989)

20% (1983)

35% (1987)

20% (1985)

20% (1999)

20% (2003)

30% (1999)