Year Percent 2000 29 2001 25 2002 34 2003 41 2004 37 2005 35 2006 36 2007 47 2008 58 2009 61 2010 67 2011 72 2012 72 2013 76 2014 80 2015 87 2016 87 2017 77 2018 69 2019 73 2020 66