Year	Cases per 100,000
1983	84.59
1984	75.33
1985	82.6
1986	77.83
1987	74.21
1988	76.95
1989	78.62
1990	78.02
1991	73.48
1992	69.31
1993	74.93
1994	72.52
1995	66.76
1996	64.07
1997	62.6