Year	Cases per 100,000
1990	0
1991	0
1992	0
1993	0.1
1994	0.2
1995	0.3
1996	0.5
1997	0.7
1998	0.9
1999	1.1
2000	1.1
2001	1.1
2002	1
2003	1
2004	1.1
2005	1.1
2006	1.1
2007	1.1