Year Cases per 100,000 1990 697.7 1991 565.4 1992 382.7 1993 427.3 1994 268.3 1995 159.1 1996 102.5 1997 138.9 1998 365.2 1999 721.8 2000 801.2 2001 873.6 2002 687.4 2003 407.7 2004 222.4 2005 130.5 2006 74.71