| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1 | In-house | 7 |
70%
|
| 2 | External | 2 |
20%
|
| 3 | Both | 1 |
10%
|
| Sysmiss | 101 |