Year	Cases per 100,000
1990	1735
1991	4064
1992	5402
1993	5382
1994	7785
1995	4573
1996	3084
1997	1747
1998	1455
1999	2252
2000	1063
2001	1783
2002	1220
2003	665.5
2004	485.8
2005	305.6
2006	306.9