Year Cases per 100,000 1990 39.76 1991 39.66 1992 39.72 1993 39.81 1994 39.96 1995 40.1 1996 40.22 1997 40.2 1998 40.14 1999 40.2 2000 40.28 2001 40.25 2002 40.21 2003 40.2 2004 40.17 2005 40.02 2006 39.86 2007 39.75 2008 39.53 2009 39.25 2010 38.9 2011 38.5 2012 38.15 2013 37.9 2014 37.68 2015 37.43 2016 37.2