Year	Cases per 100,000
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	0
1998	0.1
1999	0.1
2000	0.2
2001	0.4
2002	0.8
2003	1.4
2004	2.2
2005	3.3
2006	4.4
2007	5.2