20% (1983)

20% (1985)

20% (1987)

20% (1983)

20% (1996)

20% (1997)

20% (1990)

40% (2001)

20% (1997)

70% (1995)

65% (1999)

20% (1998)

0% (1999)

40% (1996)

20% (2002)

0% (1986)

20% (1994)

20% (1995)

30% (1999)

32% (1994)