Year Cases per 100,000 1990 5.58 1991 5.61 1992 5.66 1993 5.71 1994 5.77 1995 5.83 1996 5.85 1997 5.87 1998 5.9 1999 5.93 2000 5.98 2001 5.96 2002 5.96 2003 5.97 2004 5.97 2005 5.99 2006 5.97 2007 5.94 2008 5.93 2009 5.91 2010 5.92 2011 5.87 2012 5.85 2013 5.82 2014 5.79 2015 5.77 2016 5.75