Year Cases per 100,000 1990 37.4 1991 36.92 1992 36.26 1993 35.96 1994 35.28 1995 35.21 1996 34.96 1997 34.33 1998 33.69 1999 32.79 2000 31.71 2001 31.21 2002 30.52 2003 29.9 2004 29.27 2005 28.7 2006 28.28 2007 28.06 2008 27.28 2009 26.69 2010 26.06 2011 25.68 2012 25.26 2013 24.65 2014 24.34 2015 24.3 2016 24.21