Year Cases per 100,000 1990 27.26 1991 27.76 1992 28.29 1993 28.83 1994 29.39 1995 29.98 1996 29.75 1997 29.55 1998 29.36 1999 29.17 2000 29.01 2001 28.31 2002 27.66 2003 27.03 2004 26.41 2005 25.83 2006 25.3 2007 24.77 2008 24.26 2009 23.77 2010 23.31 2011 23.09 2012 22.88 2013 22.68 2014 22.48 2015 22.28 2016 22.11