Year Percent 2000 13 2001 14 2002 16 2003 17 2004 20 2005 24 2006 27 2007 27 2008 28 2009 28 2010 29 2011 32 2012 31 2013 32 2014 35 2015 37 2016 42 2017 49 2018 57 2019 61 2020 74