Year Cases per 100,000 1990 8.11 1991 7.95 1992 7.79 1993 7.63 1994 7.48 1995 7.34 1996 6.95 1997 6.58 1998 6.24 1999 5.91 2000 5.6 2001 5.55 2002 5.51 2003 5.46 2004 5.42 2005 5.38 2006 5.38 2007 5.38 2008 5.38 2009 5.39 2010 5.39 2011 5.44 2012 5.48 2013 5.53 2014 5.58 2015 5.63 2016 5.68