| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 2 | 
                                    
                                    0.4%
                                 | |
| 1996 | 4 | 
                                    
                                    0.8%
                                 | |
| 1997 | 5 | 
                                    
                                    1%
                                 | |
| 1998 | 6 | 
                                    
                                    1.2%
                                 | |
| 1999 | 20 | 
                                    
                                    4.1%
                                 | |
| 2000 | 16 | 
                                    
                                    3.3%
                                 | |
| 2001 | 37 | 
                                    
                                    7.5%
                                 | |
| 2002 | 44 | 
                                    
                                    9%
                                 | |
| 2003 | 67 | 
                                    
                                    13.6%
                                 | |
| 2004 | 92 | 
                                    
                                    18.7%
                                 | |
| 2005 | 116 | 
                                    
                                    23.6%
                                 | |
| 2006 | 80 | 
                                    
                                    16.3%
                                 | |
| 2007 | 2 | 
                                    
                                    0.4%
                                 | |
| Sysmiss | 431 |