| Value | Category | Cases | |
|---|---|---|---|
| 1 | keyhole | 2103 |
44.2%
|
| 2 | trench | 2312 |
48.5%
|
| 3 | both keyhole and trench | 343 |
7.2%
|
| 4 | other | 5 |
0.1%
|
| Sysmiss | 2011 |