Year Cases per 100,000 1990 4.08 1991 4.1 1992 4.13 1993 4.15 1994 4.18 1995 4.21 1996 4.21 1997 4.22 1998 4.24 1999 4.25 2000 4.26 2001 4.25 2002 4.25 2003 4.25 2004 4.24 2005 4.25 2006 4.24 2007 4.23 2008 4.23 2009 4.22 2010 4.23 2011 4.2 2012 4.19 2013 4.17 2014 4.15 2015 4.14 2016 4.13