Year Cases per 100,000 1990 19.99 1991 18.87 1992 18.27 1993 17.88 1994 17.63 1995 17.39 1996 16.91 1997 16.67 1998 16.42 1999 15.96 2000 15.47 2001 15.08 2002 14.86 2003 14.5 2004 14.13 2005 13.77 2006 13.21 2007 12.77 2008 12.42 2009 12.35 2010 12.28 2011 12.13 2012 12.05 2013 11.72 2014 11.37 2015 11.24 2016 11.17