Year Cases per 100,000 1990 6.1 1991 6.1 1992 6.11 1993 6.12 1994 6.13 1995 6.14 1996 6.1 1997 6.07 1998 6.03 1999 6 2000 5.97 2001 5.98 2002 6.01 2003 6.03 2004 6.05 2005 6.07 2006 6.12 2007 6.17 2008 6.23 2009 6.28 2010 6.34 2011 6.39 2012 6.44 2013 6.49 2014 6.53 2015 6.58 2016 6.64