| Value | Category | Cases | |
|---|---|---|---|
| 0 | not given | 33 | 
                                    
                                    62.3%
                                 | 
| 1995 | 5 | 
                                    
                                    9.4%
                                 | |
| 1996 | 4 | 
                                    
                                    7.5%
                                 | |
| 1997 | 3 | 
                                    
                                    5.7%
                                 | |
| 4444 | marked on card | 5 | 
                                    
                                    9.4%
                                 | 
| 6666 | mother reported | 3 | 
                                    
                                    5.7%
                                 | 
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| 9999 | missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 15298 |