Year	Cases per 100,000
1980	24
1981	15
1982	15
1983	17
1984	10
1985	9
1986	7
1987	8
1988	10
1989	6
1990	10
1991	5
1992	26
1995	30
1996	26
1998	31
1999	31
2000	25
2002	33
2003	34
2004	29
2005	35
2006	33
2007	34