Year	Cases per 100,000
1990	11.8
1991	17.4
1992	27.1
1993	34.6
1994	38.2
1995	40.6
1996	42.2
1997	44.3
1998	46.3
1999	48.3
2000	50.4
2001	51.7
2002	52.1
2003	51
2004	48.2
2005	44.4
2006	40.2
2007	36.4