| Value | Category | Cases | |
|---|---|---|---|
| 0 | not given | 67 | 
                                    
                                    14%
                                 | 
| 1995 | 12 | 
                                    
                                    2.5%
                                 | |
| 1996 | 67 | 
                                    
                                    14%
                                 | |
| 1997 | 107 | 
                                    
                                    22.3%
                                 | |
| 1998 | 68 | 
                                    
                                    14.2%
                                 | |
| 1999 | 50 | 
                                    
                                    10.4%
                                 | |
| 2000 | 78 | 
                                    
                                    16.3%
                                 | |
| 4444 | marked on card | 24 | 
                                    
                                    5%
                                 | 
| 6666 | mother reported | 6 | 
                                    
                                    1.3%
                                 | 
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| 9999 | missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 14872 |