Year	Cases per 100,000
1980	25
1981	0
1982	24
1983	24
1984	15
1985	15
1986	35
1987	20
1988	14
1989	8
1990	57
1993	7
1995	11
1996	20
1997	23
1998	14
1999	26
2000	25
2001	23
2002	35
2003	12
2004	21
2005	16