Year % of adults 2004 3.257142857142857 2005 3.14 2006 6.237500000000001 2007 10.6875 2008 15.675 2009 16.97647058823529 2010 17.60588235294118 2011 24.970588235294116 2012 25.78235294117647 2013 28.982352941176472 2014 28.58235294117647 2015 33.370588235294115 2016 33.07058823529412 2017 36.28235294117647 2018 40.05294117647058 2019 42.12941176470589