Year Cases per 100,000 1990 17.53 1991 18.04 1992 17.45 1993 18.57 1994 18.88 1995 18.81 1996 17.99 1997 17.17 1998 17.03 1999 16.26 2000 16.08 2001 16.69 2002 16.12 2003 16.16 2004 15.98 2005 16.43 2006 16.84 2007 17.13 2008 17.15 2009 15.04 2010 14.97 2011 14.67 2012 13.81 2013 13.29 2014 12.19 2015 12.21 2016 12.09