Year	Cases per 100,000
1980	5
1981	6
1982	3
1983	40
1984	28
1985	28
1986	24
1987	20
1988	52
1989	44
1990	42
1991	46
1992	41
1993	43
1994	48
1995	45
1996	26
1997	29
1998	35
1999	58
2002	56
2003	49
2004	50
2005	62
2007	55