30% (1989)

57% (2005)

50% (2008)

52% (2011)

30% (1991)

25% (2001)

68% (2007)

20% (1979)

30% (2004)

62% (1985)

20% (1992)

20% (1979)

43% (1984)

54% (2004)

27% (2009)

44% (1994)

60% (2007)

53% (2012)

64% (1988)

48% (2006)