Year Cases per 100,000 2000 6.2 2001 7.5 2002 6.9 2003 7.6 2004 6.8 2005 6.6 2006 7.1 2007 4.7 2008 7 2009 6.9 2010 7.7 2011 5.7 2012 5.2 2013 5 2015 5.7 2016 6.2 2017 6.3 2018 6.2 2019 5.3 2020 3.6