| Value | Category | Cases | |
|---|---|---|---|
| 2015 | 187 |
5.3%
|
|
| 2016 | 527 |
14.8%
|
|
| 2017 | 581 |
16.3%
|
|
| 2018 | 247 |
6.9%
|
|
| 9997 | 19 |
0.5%
|
|
| 9999 | NO RESPONSE | 18 |
0.5%
|
| Sysmiss | 1981 |
55.6%
|