76% (2006)

71% (2003)

62% (2000)

70% (2005)

76% (2011)

67% (2009)

68% (1999)

37% (2004)

76% (2001)

75% (2006)

73% (2007)

66% (2002)

63% (2000)

52% (1996)

65% (2004)

68% (2010)

63% (2008)

52% (2004)

66% (2009)

61% (2007)