Year Cases per 100,000 1990 6.34 1991 6.37 1992 6.4 1993 6.43 1994 6.47 1995 6.51 1996 6.47 1997 6.44 1998 6.42 1999 6.39 2000 6.38 2001 6.29 2002 6.21 2003 6.14 2004 6.06 2005 5.99 2006 5.98 2007 5.96 2008 5.95 2009 5.94 2010 5.93 2011 5.93 2012 5.94 2013 5.95 2014 5.96 2015 5.98 2016 6