| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
2.3%
|
| 2012 | 3 |
7%
|
|
| 2013 | 1 |
2.3%
|
|
| 2015 | 1 |
2.3%
|
|
| 2016 | 4 |
9.3%
|
|
| 2017 | 7 |
16.3%
|
|
| 2018 | 13 |
30.2%
|
|
| 2019 | 13 |
30.2%
|
|
| Sysmiss | 77 |