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	0.6
2001	0.8
2002	0.9
2003	0.9
2004	1
2005	1
2006	1
2007	1