Year Cases per 100,000 2000 43 2001 53 2002 51 2003 37 2004 30 2005 36 2006 29 2007 21 2008 29 2009 28 2010 45 2011 22 2012 25 2013 35 2014 20 2015 22 2016 33 2017 31 2018 26 2019 23 2020 20