Year Cases per 100,000 1990 16.41 1991 16.71 1992 17.02 1993 17.34 1994 17.66 1995 18 1996 17.85 1997 17.7 1998 17.56 1999 17.42 2000 17.29 2001 17.5 2002 17.71 2003 17.94 2004 18.17 2005 18.41 2006 18.37 2007 18.35 2008 18.34 2009 18.34 2010 18.36 2011 17.98 2012 17.61 2013 17.25 2014 16.9 2015 16.56 2016 16.23