Year Cases per 100,000 1990 3.6 1991 3.58 1992 3.58 1993 3.57 1994 3.63 1995 3.68 1996 3.76 1997 3.74 1998 3.68 1999 3.72 2000 3.84 2001 3.88 2002 3.95 2003 4.09 2004 4.18 2005 4.22 2006 4.16 2007 4.16 2008 4.17 2009 4.18 2010 4.13 2011 4.15 2012 4.2 2013 4.19 2014 4.17 2015 4.16 2016 4.15