Year Cases per 100,000 1990 7.8 1991 7.61 1992 7.44 1993 7.27 1994 7.15 1995 7.05 1996 6.95 1997 6.87 1998 6.83 1999 6.95 2000 7.06 2001 7.26 2002 7.35 2003 7.23 2004 6.97 2005 6.79 2006 6.85 2007 6.76 2008 6.85 2009 7.11 2010 6.96 2011 6.79 2012 6.5 2013 6.28 2014 6.12 2015 5.95 2016 5.79