Year	Cases per 100,000
1981	2
1982	3
1983	10
1984	15
1985	70
1986	81
1987	90
1991	29
1992	28
1994	28
1995	28
1996	23
1997	19
1998	17
1999	18
2000	15
2001	14
2002	11
2003	10
2004	10
2005	10
2006	9
2007	12