20% (2006)

0% (2003)

0% (1981)

20% (1994)

0% (1985)

20% (1996)

20% (1992)

20% (1997)

20% (1999)

35% (2004)

20% (1989)

20% (1977)

30% (1984)

0% (1995)

40% (1988)

53% (1970)

20% (1993)

0% (1987)

0% (1992)

49% (1990)