Year Cases per 100,000 1990 17.3 1991 27.3 1992 40.2 1993 56.9 1994 76.2 1995 97.5 1996 118.2 1997 140.3 1998 162.3 1999 184.8 2000 208.3 2001 230.7 2002 250.5 2003 264.2 2004 269.1 2005 267.6 2006 262.2 2007 257.8