| Value | Category | Cases | |
|---|---|---|---|
| 0 | not given | 767 | 
                                    
                                    37.5%
                                 | 
| 1995 | 33 | 
                                    
                                    1.6%
                                 | |
| 1996 | 79 | 
                                    
                                    3.9%
                                 | |
| 1997 | 144 | 
                                    
                                    7%
                                 | |
| 1998 | 208 | 
                                    
                                    10.2%
                                 | |
| 1999 | 478 | 
                                    
                                    23.4%
                                 | |
| 2000 | 243 | 
                                    
                                    11.9%
                                 | |
| 4444 | marked on card | 62 | 
                                    
                                    3%
                                 | 
| 6666 | mother reported | 33 | 
                                    
                                    1.6%
                                 | 
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| 9999 | missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 13304 |