Year % of adults 2004 0.9678571428571429 2005 1.7588235294117647 2006 1.872463768115942 2007 3.971014492753623 2008 3.2202898550724637 2009 3.347142857142858 2010 4.000000000000001 2011 3.9428571428571435 2012 4.540277777777778 2013 5.179999999999999 2014 6.201333333333333 2015 7.072368421052632 2016 7.625 2017 8.380263157894735 2018 9.549999999999999 2019 10.901315789473685