Year Cases per 100,000 1990 7.87 1991 7.65 1992 7.44 1993 7.24 1994 7.04 1995 6.85 1996 6.6 1997 6.36 1998 6.13 1999 5.91 2000 5.7 2001 5.6 2002 5.51 2003 5.41 2004 5.32 2005 5.24 2006 5.28 2007 5.32 2008 5.37 2009 5.42 2010 5.47 2011 5.5 2012 5.54 2013 5.58 2014 5.62 2015 5.66 2016 5.71