Year Cases per 100,000 1983 2.4275 1984 2.995 1985 2.7225 1986 3.37 1987 3.1875 1988 2.915 1989 3.5125 1990 3.7 1991 3.85 1992 4.01 1993 4.18 1994 4.36 1995 4.55 1996 4.67 1997 4.79 1998 4.93 1999 5.06 2000 5.21 2001 5.32 2002 5.44 2003 5.56 2004 5.68 2005 5.81 2006 6.01 2007 6.22 2008 6.43 2009 6.66 2010 6.89 2011 6.97 2012 7.06 2013 7.15 2014 7.24 2015 7.33 2016 7.42