Year % of adults 2004 4.064444444444445 2005 3.681132075471698 2006 4.120754716981132 2007 4.8999999999999995 2008 5.527777777777778 2009 6.083333333333332 2010 6.362962962962962 2011 6.294444444444443 2012 7.183928571428571 2013 8.27704918032787 2014 8.524590163934427 2015 8.90983606557377 2016 9.401639344262291 2017 9.368852459016393 2018 10.024590163934427 2019 9.880327868852456