Year Cases per 100,000 1990 19.16 1991 18.76 1992 18.37 1993 17.99 1994 17.62 1995 17.26 1996 16.84 1997 16.43 1998 16.03 1999 15.65 2000 15.28 2001 14.88 2002 14.5 2003 14.13 2004 13.78 2005 13.43 2006 13.16 2007 12.88 2008 12.62 2009 12.37 2010 12.13 2011 11.79 2012 11.48 2013 11.17 2014 10.87 2015 10.58 2016 10.31