Year Cases per 100,000 1990 5.15 1991 5.01 1992 4.87 1993 4.73 1994 4.6 1995 4.47 1996 4.34 1997 4.22 1998 4.1 1999 3.99 2000 3.88 2001 3.94 2002 4.01 2003 4.07 2004 4.14 2005 4.22 2006 4.19 2007 4.17 2008 4.15 2009 4.12 2010 4.1 2011 4.14 2012 4.17 2013 4.21 2014 4.25 2015 4.29 2016 4.33