| Value | Category | Cases | |
|---|---|---|---|
| 2015 | 107 |
3%
|
|
| 2016 | 506 |
14.2%
|
|
| 2017 | 542 |
15.2%
|
|
| 2018 | 257 |
7.2%
|
|
| 9997 | 7 |
0.2%
|
|
| 9999 | NO RESPONSE | 18 |
0.5%
|
| Sysmiss | 2123 |
59.6%
|