Year Cases per 100,000 1990 6.67 1991 6.63 1992 6.6 1993 6.58 1994 6.55 1995 6.53 1996 6.49 1997 6.46 1998 6.43 1999 6.4 2000 6.38 2001 6.34 2002 6.3 2003 6.27 2004 6.24 2005 6.22 2006 6.16 2007 6.09 2008 6.04 2009 5.98 2010 5.93 2011 5.9 2012 5.88 2013 5.86 2014 5.84 2015 5.82 2016 5.81