Year Percent 2004 9.9 2005 8.35 2006 7.24 2008 5.92 2009 6.55 2010 5.83 2011 5.39 2012 5.57 2013 5.23 2014 5.63 2017 6.39 2018 7.26 2019 7.95 2020 9.17