| Value | Category | Cases | |
|---|---|---|---|
| 0 | Not given | 256 |
3.7%
|
| 2014 | 199 |
2.8%
|
|
| 2015 | 444 |
6.3%
|
|
| 2016 | 666 |
9.5%
|
|
| 2017 | 12 |
0.2%
|
|
| 4444 | Marked on card | 28 |
0.4%
|
| 6666 | Mother reported | 26 |
0.4%
|
| 9997 | Inconsistent | 3 |
0%
|
| 9999 | Missing | 1 |
0%
|
| Sysmiss | 5370 |
76.7%
|