Year Cases per 100,000 1990 1.99 1991 1.96 1992 1.93 1993 1.9 1994 1.87 1995 1.85 1996 1.87 1997 1.9 1998 1.93 1999 1.96 2000 1.99 2001 2 2002 2.01 2003 2.03 2004 2.04 2005 2.07 2006 2.08 2007 2.1 2008 2.12 2009 2.14 2010 2.16 2011 2.18 2012 2.21 2013 2.24 2014 2.27 2015 2.3 2016 2.33