Year	Cases per 100,000
1990	4.7
1991	5.9
1992	7
1993	8.1
1994	9.1
1995	9.9
1996	10.6
1997	11.1
1998	11.5
1999	11.7
2000	11.7
2001	11.6
2002	11.4
2003	11.1
2004	10.7
2005	10.3
2006	9.8
2007	9.3