| Value | Category | Cases | |
|---|---|---|---|
| 2015 | 54 |
1.5%
|
|
| 2016 | 483 |
13.6%
|
|
| 2017 | 510 |
14.3%
|
|
| 2018 | 271 |
7.6%
|
|
| 9997 | 9 |
0.3%
|
|
| 9999 | NO RESPONSE | 18 |
0.5%
|
| Sysmiss | 2215 |
62.2%
|