| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 82 | 
                                                                 
                                    
                                    5.6%
                                 
                                                             | 
                                                        
                    |
| 1997 | 158 | 
                                                                 
                                    
                                    10.8%
                                 
                                                             | 
                                                        
                    |
| 1998 | 250 | 
                                                                 
                                    
                                    17.1%
                                 
                                                             | 
                                                        
                    |
| 1999 | 439 | 
                                                                 
                                    
                                    30.1%
                                 
                                                             | 
                                                        
                    |
| 2000 | 531 | 
                                                                 
                                    
                                    36.4%
                                 
                                                             | 
                                                        
                    |
| 9997 | inconsistent | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 9998 | dk | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 5295 |