Year	Cases per 100,000
1990	3.3
1991	5.426
1992	7.321
1993	11.04
1994	42.37
1995	105.7
1996	282.9
1997	501.8
1998	321.5
1999	221.3
2000	308.8
2001	182.3
2002	97.5
2003	84.94
2004	27.89
2005	21.34
2006	11.69