Year Cases per 100,000 1990 6.16 1991 6.3 1992 6.45 1993 6.6 1994 6.75 1995 6.92 1996 6.9 1997 6.89 1998 6.88 1999 6.87 2000 6.87 2001 6.66 2002 6.46 2003 6.27 2004 6.08 2005 5.91 2006 5.8 2007 5.68 2008 5.58 2009 5.47 2010 5.37 2011 5.36 2012 5.35 2013 5.34 2014 5.33 2015 5.33 2016 5.32