Year Percent 2003 32.96783 2004 37.83261 2005 37.37625 2006 48.01172 2007 49.34963 2008 51.16014 2009 58.40779 2010 37.263 2011 34.75313 2012 48.03282 2013 45.93159 2014 45.17869 2015 40.58725 2016 34.20185 2017 36.38707