Year	Cases per 100,000
1990	0
1991	0.1
1992	0.2
1993	0.4
1994	0.9
1995	1.8
1996	3.5
1997	6.3
1998	10.5
1999	15.6
2000	20.5
2001	24.4
2002	27.2
2003	29.2
2004	30.7
2005	31.9
2006	33
2007	34.1