| Value | Category | Cases | |
|---|---|---|---|
| 2015 | 143 |
4%
|
|
| 2016 | 424 |
11.9%
|
|
| 2017 | 440 |
12.4%
|
|
| 2018 | 197 |
5.5%
|
|
| 9997 | 51 |
1.4%
|
|
| 9999 | NO RESPONSE | 18 |
0.5%
|
| Sysmiss | 2287 |
64.2%
|