Year	Cases per 100,000
1990	9.8
1991	13.9
1992	18.7
1993	23.5
1994	27.8
1995	31.3
1996	34
1997	36.1
1998	37.6
1999	38.8
2000	39.9
2001	41
2002	42.2
2003	43.7
2004	45.5
2005	47.7
2006	50.5
2007	54