Year % of adults 2005 0.2 2006 0.2 2007 0.2 2008 0.2 2009 0.2 2010 0.2 2011 0.2 2012 0.2 2013 0.3 2014 0.3 2015 0.4 2016 0.4 2017 0.4 2018 0.4 2019 0.4