Year	Cases per 100,000
1990	14.5
1991	15.9
1992	16.3
1993	16
1994	15.5
1995	14.9
1996	14.4
1997	13.9
1998	13.6
1999	13.4
2000	13.2
2001	13.1
2002	13
2003	12.9
2004	12.9
2005	12.9
2006	13
2007	13.1