| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 |
8.8%
|
| 1 | Airport | 4 |
3.9%
|
| 2 | Land border crossing | 79 |
77.5%
|
| 3 | Seaport or waterway | 10 |
9.8%
|
| Sysmiss | 218 |