| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1 | Airport | 0 |
0%
|
| 2 | Land border crossing | 1 |
100%
|
| 3 | Seaport or waterway | 0 |
0%
|
| Sysmiss | 156 |