Year % of adults 2004 8.112987012987013 2005 7.973333333333334 2006 9.236263736263739 2007 12.156043956043957 2008 12.873626373626374 2009 14.798913043478263 2010 15.588043478260872 2011 17.35978260869565 2012 18.00744680851064 2013 19.75098039215686 2014 20.572549019607845 2015 22.508823529411774 2016 22.555882352941175 2017 23.701960784313737 2018 25.700980392156872 2019 28.31274509803921