Year % of adults 2004 0.1 2005 0.1 2006 0.1 2007 1.5 2008 2.1 2009 2.3 2010 3.3 2011 4.5 2012 4.9 2013 4.7 2014 4.9 2015 14.3 2016 25.8 2017 30.4 2018 29.9 2019 36.4