Year	Cases per 100,000
1990	0
1991	0
1992	0
1993	0
1994	0.1
1995	0.1
1996	0.1
1997	0.1
1998	0.1
1999	0.2
2000	0.3
2001	0.4
2002	0.5
2003	0.6
2004	0.7
2005	0.7
2006	0.8
2007	0.9