| Value | Category | Cases | |
|---|---|---|---|
| 2014 | 40 |
29.4%
|
|
| 2015 | 34 |
25%
|
|
| 2016 | 30 |
22.1%
|
|
| 2017 | 32 |
23.5%
|
|
| Sysmiss | 0 |