Year Percent 2005-01-01 4.41428053748066 2006-01-01 4.04630470070917 2007-01-01 3.60565330008668 2008-01-01 3.73699002301653 2009-01-01 5.03075507450451 2010-01-01 5.31570603792152 2011-01-01 5.29470665831470 2012-01-01 5.99640880360908