Year Cases per 100,000 1990 6.78 1991 6.68 1992 6.58 1993 6.55 1994 6.41 1995 6.32 1996 6.27 1997 6.21 1998 6.15 1999 6.04 2000 5.97 2001 5.91 2002 5.91 2003 5.93 2004 5.9 2005 5.87 2006 5.82 2007 5.77 2008 5.76 2009 5.77 2010 5.78 2011 5.82 2012 5.85 2013 5.89 2014 5.93 2015 5.97 2016 6.01