Year % of adults 2004 0.3 2005 0.3 2006 0.3 2007 0.1 2008 0.1 2009 0.1 2010 0 2011 0.1 2012 0.1 2013 2.2 2014 2.6 2015 3 2016 3 2017 5.1 2018 6.3 2019 10.4