| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1 | In-house | 7 |
58.3%
|
| 2 | External | 0 |
0%
|
| 3 | Both | 5 |
41.7%
|
| Sysmiss | 37 |