Year Cases per 100,000 1990 20.94 1991 20.85 1992 20.77 1993 20.69 1994 20.61 1995 20.54 1996 20.16 1997 19.79 1998 19.44 1999 19.08 2000 18.74 2001 17.69 2002 16.7 2003 15.77 2004 14.9 2005 14.08 2006 13.6 2007 13.13 2008 12.69 2009 12.26 2010 11.86 2011 11.69 2012 11.52 2013 11.35 2014 11.19 2015 11.03 2016 10.88