Year	Cases per 100,000
1990	1.6
1991	1.9
1992	2.4
1993	2.9
1994	3.6
1995	4.4
1996	5.3
1997	6.5
1998	7.9
1999	9.5
2000	11.4
2001	13.6
2002	16.1
2003	19
2004	22.1
2005	25.7
2006	29.6
2007	34