| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
1.3%
|
| 1 | Airport | 16 |
20.3%
|
| 2 | Land border crossing | 6 |
7.6%
|
| 3 | Seaport or waterway | 56 |
70.9%
|
| Sysmiss | 530 |