Year Cases per 100,000 1990 19.95 1991 19.4 1992 19.1 1993 18.32 1994 17.98 1995 17.03 1996 16.58 1997 16.36 1998 16.33 1999 16.58 2000 16.75 2001 16.78 2002 16.82 2003 16.65 2004 16.36 2005 15.92 2006 15.03 2007 14.61 2008 14.64 2009 13.64 2010 12.74 2011 12.14 2012 11.66 2013 11.27 2014 11.05 2015 10.89 2016 10.76