Year Percent 2002 3.90437 2003 2.4167 2004 1.8896 2005 1.49432 2006 1.31474 2007 1.18695 2008 1.22133 2009 1.37762 2010 1.28127 2011 1.13737 2012 1.14687 2013 1.08851 2014 1.02787 2015 0.9717 2016 0.96251 2017 0.89938