Year Cases per 100,000 1990 2.61 1991 3.02 1992 3.51 1993 4.07 1994 4.73 1995 5.5 1996 6.02 1997 6.6 1998 7.23 1999 7.93 2000 8.71 2001 8.52 2002 8.35 2003 8.18 2004 8.02 2005 7.86 2006 8.01 2007 8.16 2008 8.32 2009 8.48 2010 8.65 2011 8.62 2012 8.61 2013 8.59 2014 8.58 2015 8.56 2016 8.55