Year Cases per 100,000 1990 8.81 1991 8.76 1992 8.72 1993 8.68 1994 8.65 1995 8.62 1996 8.41 1997 8.21 1998 8.02 1999 7.83 2000 7.66 2001 7.45 2002 7.25 2003 7.06 2004 6.88 2005 6.7 2006 6.55 2007 6.4 2008 6.26 2009 6.12 2010 5.99 2011 5.98 2012 5.97 2013 5.96 2014 5.95 2015 5.94 2016 5.93