Year	Cases per 100,000
1990	2.8
1991	3.6
1992	4.4
1993	5.4
1994	6.6
1995	8
1996	9.5
1997	11.2
1998	12.9
1999	14.8
2000	16.8
2001	18.6
2002	20.3
2003	21.9
2004	23.4
2005	24.6
2006	25.7
2007	26.7