Year % of adults 2004 10.964705882352941 2005 11.1 2006 11.500000000000002 2007 12.216666666666667 2008 12.552631578947368 2009 15.405263157894733 2010 16.489473684210523 2011 18.169999999999998 2012 20.109999999999996 2013 21.345 2014 21.520000000000003 2015 22.165000000000003 2016 25.365000000000002 2017 32.355000000000004 2018 36.92 2019 37.385000000000005