Year Cases per 100,000 1990 21.82 1991 22.5 1992 22.79 1993 23.08 1994 22.77 1995 22.54 1996 21.01 1997 19.19 1998 17.35 1999 17.04 2000 16.66 2001 15.97 2002 15.63 2003 15.5 2004 15.53 2005 15.76 2006 15.19 2007 15.66 2008 15.78 2009 14.51 2010 13.83 2011 13.21 2012 13.44 2013 13.36 2014 12.39 2015 12.36 2016 12.43