Year Percent 2000 55 2001 58 2002 52 2003 58 2004 55 2005 51 2006 49 2007 48 2008 47 2009 45 2010 43 2011 41 2012 45 2013 43 2014 44 2015 48 2016 51 2017 58 2018 56 2019 62 2020 56