Year	Cases per 100,000
1990	4.7
1991	5.4
1992	6.1
1993	6.9
1994	7.6
1995	8.2
1996	8.6
1997	8.8
1998	8.8
1999	8.6
2000	8.2
2001	8.2
2002	8
2003	7.6
2004	7
2005	6.6
2006	6.3
2007	5.9