| Value | Category | Cases | |
|---|---|---|---|
| 2015 | 38 |
0.4%
|
|
| 2016 | 1390 |
13.7%
|
|
| 2017 | 1690 |
16.6%
|
|
| 2018 | 324 |
3.2%
|
|
| 9999 | NO RESPONSE | 22 |
0.2%
|
| Sysmiss | 6692 |
65.9%
|