Year Cases per 100,000 2000 5.6 2001 11 2002 5.5 2003 0 2004 5.3 2005 5.2 2006 5.2 2008 11 2009 11 2010 0 2011 5.5 2012 5.6 2013 11 2014 11 2015 0 2016 11 2017 0 2018 0 2019 5.7 2020 5.7