Year Percent 2002 8.17291 2003 7.53784 2004 8.11727 2005 7.89324 2006 8.17882 2007 9.69698 2008 10.5552 2009 9.64778 2010 10.00304 2011 10.15469 2012 11.08249 2013 12.07885 2014 14.62663 2015 14.16824 2016 15.26111