61% (2006)

53% (2007)

63% (2006)

57% (2007)

60% (2005)

63% (2006)

62% (2003)

64% (2006)

66% (2005)

62% (2006)

71% (2010)

65% (2006)

48% (2002)

60% (1998)

62% (2009)

0% (1970)