35% (2009)

54% (2004)

20% (1979)

54% (2008)

30% (2010)

62% (1985)

20% (1985)

71% (2007)

61% (2005)

52% (2011)

50% (1988)

30% (1991)

53% (2007)

20% (1979)

60% (2007)

20% (2011)

48% (2006)

56% (1978)

20% (2000)

20% (1989)