Year Cases per 100,000 1990 50.87 1991 46.74 1992 43.8 1993 41.3 1994 38.63 1995 36.3 1996 34.96 1997 33.73 1998 31.9 1999 33.47 2000 34.66 2001 36.33 2002 37.68 2003 38.65 2004 39.99 2005 40.74 2006 41.46 2007 41.59 2008 41.12 2009 40.62 2010 40.2 2011 40.18 2012 40.01 2013 40.06 2014 40.13 2015 40.21 2016 40.41