| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
1.1%
|
| 1 | Airport | 4 |
4.3%
|
| 2 | Land border crossing | 74 |
79.6%
|
| 3 | Seaport or waterway | 14 |
15.1%
|
| Sysmiss | 166 |