| Value | Category | Cases | |
|---|---|---|---|
| 0 | not given | 83 | 
                                    
                                    17.3%
                                 | 
| 1995 | 40 | 
                                    
                                    8.4%
                                 | |
| 1996 | 106 | 
                                    
                                    22.1%
                                 | |
| 1997 | 98 | 
                                    
                                    20.5%
                                 | |
| 1998 | 66 | 
                                    
                                    13.8%
                                 | |
| 1999 | 28 | 
                                    
                                    5.8%
                                 | |
| 2000 | 11 | 
                                    
                                    2.3%
                                 | |
| 4444 | marked on card | 41 | 
                                    
                                    8.6%
                                 | 
| 6666 | mother reported | 6 | 
                                    
                                    1.3%
                                 | 
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| 9999 | missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 14872 |