| Value | Category | Cases | |
|---|---|---|---|
| 2017 | 32 |
2.9%
|
|
| 2018 | 82 |
7.5%
|
|
| 2019 | 59 |
5.4%
|
|
| 9999 | NO RESPONSE | 2 |
0.2%
|
| Sysmiss | 921 |
84%
|