Year	Cases per 100,000
1988	43
1989	27
1990	27
1991	22
1992	19
1993	22
1994	19
1995	20
1996	22
1997	21
1998	20
1999	23
2000	17
2001	19
2002	15
2003	10
2004	11
2005	14
2006	14