Year Cases per 100,000 1990 31.31 1991 30.53 1992 29.55 1993 28.32 1994 27.74 1995 27.38 1996 26.14 1997 25.11 1998 24.4 1999 23.88 2000 23.16 2001 22.25 2002 21.51 2003 20.78 2004 20.36 2005 19.41 2006 18.76 2007 18.61 2008 18.53 2009 19.07 2010 18.8 2011 17.96 2012 17.6 2013 17.16 2014 16.67 2015 16.34 2016 16.03