| Value | Category | Cases | |
|---|---|---|---|
| 2015 | 229 |
6.4%
|
|
| 2016 | 493 |
13.8%
|
|
| 2017 | 525 |
14.7%
|
|
| 2018 | 217 |
6.1%
|
|
| 9997 | 14 |
0.4%
|
|
| 9999 | NO RESPONSE | 18 |
0.5%
|
| Sysmiss | 2064 |
58%
|