Year Percent 2004 10.22 2005 8.62 2006 7.25 2008 4.65 2009 5.08 2010 4.53 2011 4.14 2012 4.17 2013 3.76 2014 3.57 2017 4.29 2018 5.07 2019 5.53 2020 8.29