| Value | Category | Cases | |
|---|---|---|---|
| 0 | Not given | 65 |
0.9%
|
| 2013 | 8 |
0.1%
|
|
| 2014 | 274 |
3.9%
|
|
| 2015 | 483 |
6.9%
|
|
| 2016 | 719 |
10.3%
|
|
| 2017 | 14 |
0.2%
|
|
| 4444 | Marked on card | 41 |
0.6%
|
| 6666 | Mother reported | 26 |
0.4%
|
| 9997 | Inconsistent | 5 |
0.1%
|
| Sysmiss | 5370 |
76.7%
|