Year Cases per 100,000 1990 20.45 1991 19.69 1992 18.97 1993 18.28 1994 17.62 1995 17 1996 17 1997 17.02 1998 17.04 1999 17.06 2000 17.09 2001 17.03 2002 16.98 2003 16.93 2004 16.88 2005 16.85 2006 16.83 2007 16.8 2008 16.79 2009 16.77 2010 16.77 2011 16.76 2012 16.78 2013 16.79 2014 16.8 2015 16.81 2016 16.84