Year Percent 2002 5.23 2003 5.77 2004 5.66 2005 5.27 2006 5.13 2007 3.24 2008 2.73 2009 4.07 2010 5.1577 2011 4.9531 2012 3.842 2013 3.8428 2014 2.9749 2015 2.427 2016 2.6809 2017 3.211