20% (1976)

20% (1979)

20% (1997)

10% (1970)

20% (1987)

20% (1989)

60% (1992)

35% (1979)

23% (2006)

0% (1972)

50% (1993)

20% (2001)

20% (1990)

45% (1997)

35% (2001)

20% (1988)

0% (1963)

20% (1989)

20% (1998)

0% (1988)