Year per 1,000 adults 2004 0.02 2005 0.05 2006 0.13 2007 0.29 2008 0.51 2009 0.67 2010 1.1 2011 1.46 2012 3.48 2013 3.26 2014 4.76 2015 9.42 2016 9.94 2017 9.72 2018 9.74