| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.8%
|
| 1 | Airport | 20 |
15.9%
|
| 2 | Land border crossing | 10 |
7.9%
|
| 3 | Seaport or waterway | 95 |
75.4%
|
| Sysmiss | 219 |