Year	Cases per 100,000
1990	60
1991	98.2
1992	143.4
1993	189.1
1994	230
1995	256.7
1996	265.2
1997	277.8
1998	287.4
1999	291.9
2000	297
2001	289.1
2002	289.3
2003	284.1
2004	279.2
2005	268.4
2006	251.8
2007	235.5