Year % of adults 2004 0.1 2005 0.8 2006 3.4 2007 1 2008 4.9 2009 1.8 2010 2.9 2011 3.6 2012 9.1 2013 8.9 2014 5.4 2015 6.5 2016 8 2017 8 2018 11.1 2019 40.1