| Value | Category | Cases | |
|---|---|---|---|
| 0 | Not given | 18 |
0.3%
|
| 2013 | 8 |
0.1%
|
|
| 2014 | 281 |
4%
|
|
| 2015 | 511 |
7.3%
|
|
| 2016 | 764 |
10.9%
|
|
| 2017 | 14 |
0.2%
|
|
| 4444 | Marked on card | 23 |
0.3%
|
| 6666 | Mother reported | 12 |
0.2%
|
| 9997 | Inconsistent | 4 |
0.1%
|
| Sysmiss | 5370 |
76.7%
|