| Value | Category | Cases | |
|---|---|---|---|
| 0 | None | 53 |
20.5%
|
| 2014 | 60 |
23.2%
|
|
| 2015 | 89 |
34.4%
|
|
| 2016 | 56 |
21.6%
|
|
| 4444 | Marked on card | 1 |
0.4%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 864 |