| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1.Mandatory | 13 |
19.1%
|
| 2 | 2.Voluntary | 9 |
13.2%
|
| 6 | 6.Free | 46 |
67.6%
|
| 9 | 9.Missing | 0 |
0%
|
| Sysmiss | 363 |