Year Percent 2000 2.8 2001 5.2 2002 12 2003 17 2004 22 2005 32 2006 39 2007 50 2008 52 2009 55 2010 53 2011 52 2012 52 2013 55 2014 58 2015 60 2016 65 2017 65 2018 64 2019 58 2020 48