| Value | Category | Cases | |
|---|---|---|---|
| 2015 | 2 |
0.1%
|
|
| 2016 | 29 |
0.8%
|
|
| 2017 | 493 |
13.8%
|
|
| 2018 | 212 |
6%
|
|
| 9997 | 7 |
0.2%
|
|
| 9999 | NO RESPONSE | 18 |
0.5%
|
| Sysmiss | 2799 |
78.6%
|