Year Cases per 100,000 1990 3.72 1991 3.69 1992 3.65 1993 3.68 1994 3.68 1995 3.67 1996 3.63 1997 3.58 1998 3.51 1999 3.42 2000 3.35 2001 3.32 2002 3.29 2003 3.21 2004 3.2 2005 3.17 2006 3.17 2007 3.19 2008 3.14 2009 3.16 2010 3.16 2011 3.03 2012 2.96 2013 2.92 2014 2.88 2015 2.83 2016 2.78