Year % of adults 2004 0.1 2005 2.3 2006 2.9 2007 2.5 2008 4.1 2009 4 2010 2.9 2011 3.7 2012 3.3 2013 3.7 2014 3.6 2015 0.1 2016 0.1 2017 0.1 2018 0.1 2019 0