Year Percent 2000 40 2001 42 2002 43 2003 48 2004 54 2005 54 2006 52 2007 52 2008 53 2009 55 2010 54 2011 50 2012 48 2013 48 2014 48 2015 48 2016 51 2017 57 2018 63 2019 64 2020 70