| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1 | Airport | 9 |
6%
|
| 2 | Land border crossing | 0 |
0%
|
| 3 | Seaport or waterway | 141 |
94%
|
| Sysmiss | 91 |