Year Cases per 100,000 1990 9 1991 9.05 1992 9.14 1993 9.23 1994 9.22 1995 8.81 1996 8.93 1997 8.69 1998 8.62 1999 8.37 2000 8.33 2001 8.42 2002 8.4 2003 8.28 2004 8.03 2005 7.84 2006 7.86 2007 7.79 2008 7.75 2009 7.59 2010 7.37 2011 7.25 2012 7.01 2013 7.02 2014 7.08 2015 6.97 2016 6.91