Year	Cases per 100,000
1990	19270
1991	12650
1992	8408
1993	6408
1994	2245
1995	4830
1996	3214
1997	3402
1998	3388
1999	2772
2000	3567
2001	9747
2002	17190
2003	20960
2004	18930
2005	14990
2006	9595