Year	Cases per 100,000
1990	0.1
1991	0.2
1992	0.3
1993	0.5
1994	0.8
1995	1.3
1996	1.9
1997	2.9
1998	4.1
1999	5.6
2000	7.3
2001	9
2002	10.5
2003	11.6
2004	12.5
2005	13.1
2006	13.6
2007	13.8