Year Percent 2002 5.1853 2003 4.09221 2004 3.34262 2005 2.51001 2006 1.51764 2007 1.54142 2008 1.38365 2009 2.15807 2010 1.79953 2011 3.05767 2012 1.81559 2013 2.41549 2014 3.51668 2015 4.3863 2016 4.61178 2017 3.87478 2018 3.66013 2019 4.08879 2020 3.59386 2021 1.69937 2022 1.59722