| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 99 | 
                                                                 
                                    
                                    6.2%
                                 
                                                             | 
                                                        
                    |
| 1997 | 168 | 
                                                                 
                                    
                                    10.6%
                                 
                                                             | 
                                                        
                    |
| 1998 | 287 | 
                                                                 
                                    
                                    18.1%
                                 
                                                             | 
                                                        
                    |
| 1999 | 507 | 
                                                                 
                                    
                                    31.9%
                                 
                                                             | 
                                                        
                    |
| 2000 | 528 | 
                                                                 
                                    
                                    33.2%
                                 
                                                             | 
                                                        
                    |
| 9997 | inconsistent | 1 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    
| 9998 | dk | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 5165 |