Year Cases per 100,000 2000 4.1 2001 4 2002 6 2003 1.7 2004 4.5 2005 5.4 2006 7.4 2007 9.3 2008 12 2009 10 2010 7 2011 7.2 2012 10 2013 12 2014 10 2015 7.4 2016 11 2017 9.6 2018 13 2019 22 2020 32