Year	Cases per 100,000
1990	4.9
1991	7
1992	9.3
1993	11.7
1994	13.9
1995	15.7
1996	17
1997	18
1998	18.8
1999	19.4
2000	19.9
2001	20.5
2002	21.1
2003	21.8
2004	22.7
2005	23.8
2006	25.2
2007	27