Year Cases per 100,000 1990 5.19 1991 5.22 1992 5.26 1993 5.29 1994 5.33 1995 5.37 1996 5.39 1997 5.42 1998 5.45 1999 5.48 2000 5.51 2001 5.52 2002 5.53 2003 5.55 2004 5.56 2005 5.58 2006 5.57 2007 5.55 2008 5.54 2009 5.53 2010 5.53 2011 5.49 2012 5.47 2013 5.45 2014 5.42 2015 5.4 2016 5.39