Year Cases per 100,000 1990 25.11 1991 25.48 1992 25.86 1993 26.26 1994 26.66 1995 27.08 1996 26.86 1997 26.65 1998 26.46 1999 26.26 2000 26.09 2001 25.53 2002 25.01 2003 24.5 2004 24 2005 23.54 2006 23.32 2007 23.08 2008 22.87 2009 22.66 2010 22.46 2011 22.28 2012 22.11 2013 21.95 2014 21.78 2015 21.62 2016 21.48