Year Deaths per 100,000 1990 0 1991 0 1992 0.1 1993 0.1 1994 0.1 1995 0.2 1996 0.3 1997 0.5 1998 0.7 1999 1 2000 1.3 2001 1.5 2002 1.8 2003 1.9 2004 2.1 2005 2.3 2006 2.3 2007 2.5