Year % of adults 2004 0 2005 0 2006 0 2007 0 2008 0 2009 0 2010 0 2011 0 2012 0 2013 0 2014 0 2015 0.21818181818181817 2016 1.4909090909090907 2017 4.8 2018 5.5 2019 2.809090909090909