Year Percent 2003-01-01 6.277102947 2004-01-01 10.380472180 2005-01-01 14.681278230 2006-01-01 18.259738920 2007-01-01 21.454086300 2008-01-01 26.725515370 2009-01-01 30.444740300 2010-01-01 31.428737640 2011-01-01 32.671562190