Year Cases per 100,000 1990 8.68 1991 8.62 1992 8.57 1993 8.51 1994 8.46 1995 8.42 1996 8.38 1997 8.35 1998 8.32 1999 8.28 2000 8.26 2001 8.22 2002 8.2 2003 8.17 2004 8.14 2005 8.12 2006 8.1 2007 8.08 2008 8.06 2009 8.04 2010 8.03 2011 8.02 2012 8.01 2013 8.01 2014 8 2015 8 2016 8