Year Cases per 100,000 1990 30.89 1991 32.11 1992 32.75 1993 32.08 1994 31.5 1995 31.85 1996 30.4 1997 31.03 1998 30.01 1999 29.4 2000 29.53 2001 28.29 2002 27.03 2003 25.88 2004 24.83 2005 24.17 2006 23.79 2007 23.16 2008 22.51 2009 22.14 2010 21.71 2011 20.94 2012 20.05 2013 19.11 2014 18.3 2015 17.51 2016 17.28