| Value | Category | Cases | |
|---|---|---|---|
| 2017 | 1 |
0.1%
|
|
| 2018 | 1 |
0.1%
|
|
| 2019 | 26 |
1.3%
|
|
| 9999 | NO RESPONSE | 1 |
0.1%
|
| Sysmiss | 1938 |
98.5%
|