Year per 1,000 adults 2008 18.08 2009 16.975 2010 18.685000000000002 2011 21.450000000000003 2012 25.595 2013 26.5 2014 32.195 2015 31.16 2016 32.07 2017 30.95 2018 34.915 2019 38.885000000000005 2020 47.21