Year Percent 2002 6.2053 2003 4.5091 2004 2.4788 2005 4.2401 2006 2.9021 2007 3.0652 2008 3.0624 2009 3.1758 2010 1.6392 2011 1.9285 2012 1.573 2013 1.5344 2014 1.0318 2015 1.9539 2016 1.8924 2017 1.7474