38% (1980)

20% (1983)

40% (1998)

20% (2006)

70% (1981)

35% (1993)

60% (1974)

40% (2004)

20% (1975)

10% (1979)

90% (1973)

44% (1997)

35% (1991)

48% (1975)

0% (1995)

65% (1973)

20% (1974)

20% (1999)

0% (2003)

30% (1984)