79% (1999)

74% (1990)

79% (2002)

86% (2005)

83% (2011)

80% (2009)

82% (2004)

78% (2006)

71% (1993)

54% (1992)

60% (2009)

75% (2008)

68% (2010)

61% (2011)

75% (1993)

64% (2010)

70% (2009)

68% (2010)

50% (2011)

36% (2009)