Year Cases per 100,000 1990 2.66 1991 2.66 1992 2.67 1993 2.67 1994 2.68 1995 2.69 1996 2.68 1997 2.68 1998 2.68 1999 2.68 2000 2.68 2001 2.67 2002 2.66 2003 2.66 2004 2.65 2005 2.65 2006 2.66 2007 2.67 2008 2.69 2009 2.7 2010 2.72 2011 2.73 2012 2.74 2013 2.75 2014 2.76 2015 2.77 2016 2.79