| Value | Category | Cases | |
|---|---|---|---|
| -998 | Dont know | 18 | 
                                    
                                    13.7%
                                 | 
| -888 | Other (specify: | 2 | 
                                    
                                    1.5%
                                 | 
| 1 | Between 16-24 months (1.5 to 2 years) | 111 | 
                                    
                                    84.7%
                                 |