| Value | Category | Cases | |
|---|---|---|---|
| 0 | not given | 3 | 
                                    
                                    5.7%
                                 | 
| 1995 | 16 | 
                                    
                                    30.2%
                                 | |
| 1996 | 14 | 
                                    
                                    26.4%
                                 | |
| 1997 | 9 | 
                                    
                                    17%
                                 | |
| 1998 | 2 | 
                                    
                                    3.8%
                                 | |
| 1999 | 1 | 
                                    
                                    1.9%
                                 | |
| 2000 | 1 | 
                                    
                                    1.9%
                                 | |
| 4444 | marked on card | 7 | 
                                    
                                    13.2%
                                 | 
| 6666 | mother reported | 0 | 
                                    
                                    0%
                                 | 
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| 9999 | missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 15298 |