Year Cases per 100,000 1990 2.74 1991 2.76 1992 2.78 1993 2.8 1994 2.83 1995 2.85 1996 2.87 1997 2.88 1998 2.9 1999 2.9 2000 2.91 2001 2.93 2002 2.94 2003 2.96 2004 2.96 2005 2.98 2006 2.99 2007 3 2008 3.01 2009 3.02 2010 3.03 2011 3.06 2012 3.09 2013 3.12 2014 3.15 2015 3.17 2016 3.2