Year Percent 2002 10.57 2003 13.06 2004 14.81 2005 14.73 2006 13.19 2009 9.42 2010 8.85 2011 9.03 2012 9.33 2013 12.67 2014 12.26 2015 9.72 2016 8.69 2017 6.81