| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 2013 | 1 |
16.7%
|
|
| 2015 | 1 |
16.7%
|
|
| 2016 | 3 |
50%
|
|
| 2017 | 1 |
16.7%
|
|
| Sysmiss | 105 |