Year Cases per 100,000 1990 5 1991 5.3 1992 5.63 1993 5.97 1994 6.34 1995 6.74 1996 6.73 1997 6.73 1998 6.73 1999 6.73 2000 6.73 2001 6.86 2002 7 2003 7.14 2004 7.28 2005 7.43 2006 7.57 2007 7.71 2008 7.86 2009 8.01 2010 8.16 2011 8.39 2012 8.63 2013 8.88 2014 9.14 2015 9.4 2016 9.67