Year	Cases per 100,000
1990	5.5
1991	8.8
1992	12.5
1993	16.3
1994	19.9
1995	23
1996	25.4
1997	27.8
1998	30.2
1999	32.6
2000	35.2
2001	37.6
2002	39.5
2003	40.6
2004	40.4
2005	39.4
2006	37.9
2007	36.8