Year	Cases per 100,000
1990	0.6
1991	0.8
1992	1
1993	1.3
1994	1.8
1995	2.3
1996	3
1997	4
1998	5.2
1999	6.7
2000	8.8
2001	11.4
2002	14.7
2003	18.9
2004	24.2
2005	30.7
2006	38.9
2007	46.3