Year Cases per 100,000 1990 29.46 1991 29.86 1992 30.29 1993 30.73 1994 31.18 1995 31.67 1996 31.39 1997 31.15 1998 30.91 1999 30.68 2000 30.49 2001 29.64 2002 28.85 2003 28.09 2004 27.35 2005 26.66 2006 26.16 2007 25.64 2008 25.17 2009 24.7 2010 24.27 2011 24.09 2012 23.93 2013 23.78 2014 23.63 2015 23.48 2016 23.35