Year Cases per 100,000 2000 27 2001 25 2002 25 2003 26 2004 26 2005 26 2006 25 2007 24 2008 23 2009 23 2010 23 2011 22 2012 22 2013 22 2014 21 2015 24 2016 27 2017 36 2018 38 2019 36 2020 32