Year Cases per 100,000 1990 22.65 1991 22.16 1992 21.91 1993 22.13 1994 22.14 1995 22.38 1996 21.83 1997 21.7 1998 21.41 1999 20.43 2000 20.32 2001 20.13 2002 19.72 2003 19.28 2004 19.31 2005 19.64 2006 19.4 2007 19.49 2008 19.51 2009 20.07 2010 19.96 2011 20.37 2012 20.98 2013 21.79 2014 22.21 2015 22.72 2016 23.11