Year Percent 2003-01-01 3.33743210876727 2004-01-01 2.98594884188592 2005-01-01 2.54731208035992 2006-01-01 2.82568463665395 2007-01-01 2.23535174607957 2008-01-01 2.94444801522725 2009-01-01 7.21862065127939 2010-01-01 7.54841100861786 2011-01-01 7.03319576393798 2012-01-01 5.98346829997980 2013-01-01 5.38103506455404 2014-01-01 4.89040397309472 2015-01-01 3.96666366578696 2016-01-01 2.96862921369136 2017-01-01 2.74378753514715