| Value | Category | Cases | |
|---|---|---|---|
| 0 | not given | 253 | 
                                    
                                    52.8%
                                 | 
| 1995 | 37 | 
                                    
                                    7.7%
                                 | |
| 1996 | 65 | 
                                    
                                    13.6%
                                 | |
| 1997 | 40 | 
                                    
                                    8.4%
                                 | |
| 1998 | 23 | 
                                    
                                    4.8%
                                 | |
| 1999 | 3 | 
                                    
                                    0.6%
                                 | |
| 2000 | 7 | 
                                    
                                    1.5%
                                 | |
| 4444 | marked on card | 43 | 
                                    
                                    9%
                                 | 
| 6666 | mother reported | 8 | 
                                    
                                    1.7%
                                 | 
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| 9999 | missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 14872 |