Year	Cases per 100,000
1983	31.5
1984	33.57
1985	34.78
1986	33.24
1987	30.49
1988	33.5
1989	32.06
1990	29.39
1991	30.27
1992	29.66
1993	30.73
1994	28.09
1995	25.82
1996	24.64
1997	25.17