Year Percent 2003-01-01 17.58546066 2004-01-01 20.61977959 2005-01-01 15.80657005 2006-01-01 19.85308075 2007-01-01 23.50223923 2008-01-01 25.91970062 2009-01-01 28.94515991 2010-01-01 32.27399826 2011-01-01 29.46730042 2012-01-01 28.07701302