Year	Cases per 100,000
1980	114
1981	81
1982	79
1983	66
1984	59
1985	31
1986	27
1987	21
1988	16
1989	16
1990	15
1991	13
1992	12
1993	14
1994	14
1997	16
1998	16
1999	17
2000	17
2001	16
2002	15
2003	15
2004	14
2005	15
2006	16
2007	16