Year	Cases per 100,000
1990	5.6
1991	7.1
1992	8.8
1993	10.9
1994	13.2
1995	15.9
1996	19
1997	22.3
1998	25.9
1999	29.7
2000	33.5
2001	37.1
2002	40.6
2003	43.8
2004	46.7
2005	49.3
2006	51.5
2007	53.4