Year Cases per 100,000 1990 2.48 1991 2.49 1992 2.49 1993 2.5 1994 2.51 1995 2.51 1996 2.52 1997 2.52 1998 2.52 1999 2.52 2000 2.53 2001 2.52 2002 2.51 2003 2.5 2004 2.49 2005 2.49 2006 2.49 2007 2.5 2008 2.51 2009 2.52 2010 2.53 2011 2.53 2012 2.53 2013 2.53 2014 2.53 2015 2.53 2016 2.54