Year Cases per 100,000 1990 5.83 1991 5.85 1992 5.88 1993 5.91 1994 5.94 1995 5.98 1996 5.94 1997 5.92 1998 5.89 1999 5.86 2000 5.84 2001 5.77 2002 5.71 2003 5.64 2004 5.58 2005 5.53 2006 5.48 2007 5.43 2008 5.39 2009 5.34 2010 5.31 2011 5.27 2012 5.23 2013 5.2 2014 5.16 2015 5.13 2016 5.1