| Value | Category | Cases | |
|---|---|---|---|
| 2015 | 861 |
8.5%
|
|
| 2016 | 1653 |
16.3%
|
|
| 2017 | 1844 |
18.2%
|
|
| 2018 | 432 |
4.3%
|
|
| 9997 | INCONSISTENT | 1 |
0%
|
| 9999 | NO RESPONSE | 22 |
0.2%
|
| Sysmiss | 5343 |
52.6%
|