| Value | Category | Cases | |
|---|---|---|---|
| 2017 | 4 |
0.2%
|
|
| 2018 | 98 |
5%
|
|
| 2019 | 173 |
8.8%
|
|
| 9999 | NO RESPONSE | 1 |
0.1%
|
| Sysmiss | 1691 |
86%
|