| Value | Category | Cases | |
|---|---|---|---|
| 0 | not given | 745 | 
                                    
                                    36.4%
                                 | 
| 1995 | 32 | 
                                    
                                    1.6%
                                 | |
| 1996 | 80 | 
                                    
                                    3.9%
                                 | |
| 1997 | 144 | 
                                    
                                    7%
                                 | |
| 1998 | 209 | 
                                    
                                    10.2%
                                 | |
| 1999 | 481 | 
                                    
                                    23.5%
                                 | |
| 2000 | 248 | 
                                    
                                    12.1%
                                 | |
| 4444 | marked on card | 70 | 
                                    
                                    3.4%
                                 | 
| 6666 | mother reported | 38 | 
                                    
                                    1.9%
                                 | 
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| 9999 | missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 13304 |