| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.4%
|
| 1 | Airport | 52 |
19.4%
|
| 2 | Land border crossing | 6 |
2.2%
|
| 3 | Seaport or waterway | 209 |
78%
|
| Sysmiss | 344 |