| Value | Category | Cases | |
|---|---|---|---|
| 1993 | 1 | 
                                    
                                    0.4%
                                 | |
| 1994 | 1 | 
                                    
                                    0.4%
                                 | |
| 1995 | 1 | 
                                    
                                    0.4%
                                 | |
| 1996 | 3 | 
                                    
                                    1.2%
                                 | |
| 1997 | 4 | 
                                    
                                    1.6%
                                 | |
| 1998 | 5 | 
                                    
                                    2%
                                 | |
| 1999 | 23 | 
                                    
                                    9.4%
                                 | |
| 2000 | 49 | 
                                    
                                    20%
                                 | |
| 2001 | 118 | 
                                    
                                    48.2%
                                 | |
| 2002 | 40 | 
                                    
                                    16.3%
                                 | |
| Sysmiss | 11070 |