Year Cases per 100,000 1990 5.37 1991 5.4 1992 5.43 1993 5.47 1994 5.5 1995 5.54 1996 5.6 1997 5.66 1998 5.72 1999 5.78 2000 5.85 2001 5.91 2002 5.98 2003 6.05 2004 6.12 2005 6.19 2006 6.19 2007 6.19 2008 6.19 2009 6.19 2010 6.2 2011 6.18 2012 6.16 2013 6.14 2014 6.13 2015 6.11 2016 6.1