Year	Cases per 100,000
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0.1
1996	0.1
1997	0.2
1998	0.3
1999	0.5
2000	0.8
2001	1.2
2002	1.7
2003	2.2
2004	2.6
2005	3
2006	3.4
2007	3.7