Year	Cases per 100,000
1990	6
1991	7.7
1992	9.7
1993	12.3
1994	15.4
1995	17.6
1996	22.2
1997	26.1
1998	32.7
1999	36.7
2000	46.8
2001	51.8
2002	56.2
2003	56.9
2004	60.3
2005	66.9
2006	75.9
2007	84.8