Year	Cases per 100,000
1980	33
1981	28
1982	24
1983	27
1984	24
1985	32
1986	28
1987	24
1988	23
1989	30
1990	31
1991	34
1992	32
1993	24
1994	30
1995	26
1996	26
1997	22
1998	21
1999	24
2000	18
2001	23
2002	18
2003	23
2004	16
2005	16
2006	14
2007	11