Year	Cases per 100,000
1990	0
1991	0
1992	0
1993	0.1
1994	0.1
1995	0.1
1996	0.2
1997	0.2
1998	0.3
1999	0.4
2000	0.5
2001	0.6
2002	0.8
2003	1.1
2004	1.4
2005	1.7
2006	2.1
2007	2.5