Year Cases per 100,000 2000 20 2001 20 2002 19 2003 21 2004 22 2005 26 2006 28 2007 28 2008 29 2009 31 2010 31 2011 33 2012 31 2013 31 2014 32 2015 31 2016 30 2017 29 2018 30 2019 24 2020 27