Year % of adults 2004 1.0411764705882351 2005 0.9933333333333334 2006 1.25 2007 1.4235294117647062 2008 2.474285714285714 2009 3.0085714285714285 2010 3.3285714285714283 2011 3.310810810810811 2012 3.642105263157894 2013 5.613157894736843 2014 5.323684210526316 2015 7.189473684210526 2016 10.421052631578947 2017 9.9 2018 13.063157894736841 2019 13.85