| Value | Category | Cases | |
|---|---|---|---|
| 0 | not given | 518 | 
                                    
                                    25.3%
                                 | 
| 1995 | 46 | 
                                    
                                    2.2%
                                 | |
| 1996 | 99 | 
                                    
                                    4.8%
                                 | |
| 1997 | 157 | 
                                    
                                    7.7%
                                 | |
| 1998 | 253 | 
                                    
                                    12.4%
                                 | |
| 1999 | 590 | 
                                    
                                    28.8%
                                 | |
| 2000 | 288 | 
                                    
                                    14.1%
                                 | |
| 4444 | marked on card | 71 | 
                                    
                                    3.5%
                                 | 
| 6666 | mother reported | 25 | 
                                    
                                    1.2%
                                 | 
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| 9999 | missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 13304 |