Year Cases per 100,000 1990 3.5 1991 3.53 1992 3.56 1993 3.6 1994 3.63 1995 3.67 1996 3.67 1997 3.67 1998 3.67 1999 3.67 2000 3.67 2001 3.68 2002 3.68 2003 3.69 2004 3.7 2005 3.71 2006 3.71 2007 3.71 2008 3.71 2009 3.71 2010 3.71 2011 3.7 2012 3.7 2013 3.69 2014 3.69 2015 3.68 2016 3.68