Year Cases per 100,000 2000 0 2001 0 2002 0 2004 9.1 2006 4.5 2010 1.5 2011 1.5 2012 4.6 2013 0 2014 0 2015 0 2016 3.2 2017 3.2 2018 3.2 2019 3.2 2020 4.8