Year	Cases per 100,000
1990	13
1991	27.4
1992	52.7
1993	92.6
1994	144.5
1995	199.9
1996	247.1
1997	293.9
1998	340.1
1999	387.6
2000	415.5
2001	434.2
2002	462.4
2003	479.4
2004	485.6
2005	482.5
2006	481.6
2007	480.8