| Value | Category | Cases | |
|---|---|---|---|
| 0 | not given | 856 | 
                                    
                                    41.8%
                                 | 
| 1995 | 12 | 
                                    
                                    0.6%
                                 | |
| 1996 | 58 | 
                                    
                                    2.8%
                                 | |
| 1997 | 122 | 
                                    
                                    6%
                                 | |
| 1998 | 178 | 
                                    
                                    8.7%
                                 | |
| 1999 | 378 | 
                                    
                                    18.5%
                                 | |
| 2000 | 359 | 
                                    
                                    17.5%
                                 | |
| 4444 | marked on card | 45 | 
                                    
                                    2.2%
                                 | 
| 6666 | mother reported | 39 | 
                                    
                                    1.9%
                                 | 
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| 9999 | missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 13304 |