| Value | Category | Cases | |
|---|---|---|---|
| 2015 | 85 |
2.4%
|
|
| 2016 | 415 |
11.7%
|
|
| 2017 | 429 |
12.1%
|
|
| 2018 | 220 |
6.2%
|
|
| 9997 | 31 |
0.9%
|
|
| 9999 | NO RESPONSE | 18 |
0.5%
|
| Sysmiss | 2362 |
66.3%
|