| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 1 |
1.1%
|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 2019 | 21 |
22.8%
|
|
| 2020 | 70 |
76.1%
|
|
| Sysmiss | 1004 |