Year	Cases per 100,000
1990	4.9
1991	6.7
1992	8.7
1993	11
1994	13.6
1995	16.4
1996	19.1
1997	22.2
1998	25.4
1999	28.8
2000	32.3
2001	35.6
2002	38.4
2003	40.1
2004	40.4
2005	39.6
2006	38.2
2007	36.8