Year Cases per 100,000 1990 7.08 1991 7.05 1992 7.04 1993 7.02 1994 7 1995 6.99 1996 6.91 1997 6.83 1998 6.76 1999 6.68 2000 6.61 2001 6.52 2002 6.44 2003 6.36 2004 6.28 2005 6.2 2006 6.17 2007 6.13 2008 6.1 2009 6.07 2010 6.04 2011 5.99 2012 5.94 2013 5.89 2014 5.85 2015 5.8 2016 5.76