Year Cases per 100,000 1990 26.68 1991 26.86 1992 27.19 1993 27.6 1994 28.11 1995 29.22 1996 30.09 1997 30.73 1998 30.54 1999 29.9 2000 28.86 2001 28.13 2002 27.68 2003 27.32 2004 27.03 2005 26.65 2006 26.14 2007 25.44 2008 24.89 2009 24.84 2010 24.79 2011 24.26 2012 23.64 2013 23 2014 22.26 2015 21.98 2016 21.76