Year Cases per 100,000 1980 10.36455 1981 7.93909 1982 10.24364 1983 8.67818 1984 10.69273 1985 12.13727 1986 10.94182 1987 12.02636 1988 12.72091 1989 12.98545 1990 14.79 1991 14.97 1992 15.16 1993 15.35 1994 15.55 1995 15.75 1996 15.91 1997 16.07 1998 16.24 1999 16.41 2000 16.58 2001 16.99 2002 17.42 2003 17.87 2004 18.32 2005 18.8 2006 19.1 2007 19.4 2008 19.72 2009 20.05 2010 20.39 2011 20.93 2012 21.47 2013 22.04 2014 22.62 2015 23.21 2016 23.83