Year Cases per 100,000 2000 5.2 2001 5.1 2002 3.4 2003 5 2004 8.4 2005 10 2006 6.8 2007 5.1 2008 5.2 2009 7.1 2010 7.1 2011 5.4 2015 7.2 2017 9 2018 0 2019 1.8 2020 5.4