| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
2.7%
|
| 1 | Airport | 8 |
21.6%
|
| 2 | Land border crossing | 28 |
75.7%
|
| 3 | Seaport or waterway | 0 |
0%
|
| Sysmiss | 971 |