Year Percent 2005 3.79 2006 2.87 2007 2.68 2008 2.53 2009 2.61 2010 3.16 2011 3.55 2012 2.96 2013 4.91 2014 6.15 2015 4.89 2016 4.99 2017 4.15 2018 4.41 2019 4.8 2020 9.77