Year: 1996
Number of Cases: 252

Year: 1997
Number of Cases: 256

Year: 1998
Number of Cases: 261

Year: 1999
Number of Cases: 283

Year: 2000
Number of Cases: 465

Year: 2001
Number of Cases: 463

Year: 2002
Number of Cases: 866

Year: 2003
Number of Cases: 475

Year: 2004
Number of Cases: 1,023

Year: 2005
Number of Cases: 917

Year: 2006
Number of Cases: 913

Year: 2007
Number of Cases: 1,239

Year: 2008
Number of Cases: 1,050

Year: 2009
Number of Cases: 1,065

Year: 2010
Number of Cases: 1,293

Year: 2011
Number of Cases: 1,203

Year: 2012
Number of Cases: 912

Year: 2013
Number of Cases: 1,431