Year	Cases per 100,000
1983	42.47
1984	40.09
1985	36.6
1986	40.25
1987	37.23
1988	38.43
1989	36.54
1990	34.19
1991	35.22
1992	37.09
1993	37.8
1994	38.26
1995	32.91
1996	35.13
1997	32.6