Year Cases per 100,000 1990 16.42 1991 16.92 1992 17.5 1993 18.34 1994 18.56 1995 19.05 1996 18.71 1997 18.61 1998 18.15 1999 18.12 2000 17.66 2001 17.85 2002 18.58 2003 18.42 2004 18.62 2005 18.77 2006 18.49 2007 18.08 2008 17.96 2009 17.96 2010 17.81 2011 17.92 2012 16.58 2013 16.21 2014 15.55 2015 15.04 2016 14.74