Year Percent 2000 45 2001 45 2002 48 2003 50 2004 54 2005 56 2006 62 2007 61 2008 64 2009 63 2010 60 2011 66 2012 62 2013 60 2014 61 2015 63 2016 61 2017 55 2018 62 2019 65 2020 58