Year Cases per 100,000 1990 7.34 1991 7.34 1992 7.35 1993 7.36 1994 7.38 1995 7.4 1996 7.26 1997 7.14 1998 7.02 1999 6.9 2000 6.79 2001 6.62 2002 6.45 2003 6.29 2004 6.14 2005 5.99 2006 5.98 2007 5.96 2008 5.95 2009 5.94 2010 5.94 2011 5.95 2012 5.98 2013 6 2014 6.02 2015 6.05 2016 6.07