Year	Cases per 100,000
1980	6
1981	18
1982	17
1983	22
1984	32
1985	13
1986	19
1987	21
1988	29
1989	11
1990	19
1991	6
1992	2
1993	8
1994	8
1996	0
1997	11
1998	5
1999	7
2000	5
2001	5
2002	3
2003	5
2004	8
2005	9
2006	6
2007	4