Year Cases per 100,000 1990 31.02 1991 30.83 1992 29.75 1993 28.3 1994 27.65 1995 27.28 1996 25.88 1997 25.36 1998 24.67 1999 24.89 2000 23.59 2001 22.71 2002 22 2003 21.61 2004 21.33 2005 20.81 2006 20.38 2007 20.07 2008 19.6 2009 19.08 2010 18.65 2011 18.05 2012 17.71 2013 17.17 2014 16.3 2015 15.86 2016 15.47