Year Cases per 100,000 2002 2.9 2006 27 2007 4.2 2008 18 2009 5.6 2010 11 2011 2.8 2012 9.9 2013 4.2 2014 1.4 2015 9.8 2016 7 2017 1.4 2018 5.6 2019 14