| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 22 |
2.2%
|
| -7 | Does not apply | 76 |
7.6%
|
| 0 | No obstacle | 517 |
51.8%
|
| 1 | Minor obstacle | 161 |
16.1%
|
| 2 | Moderate obstacle | 91 |
9.1%
|
| 3 | Major obstacle | 55 |
5.5%
|
| 4 | Very severe obstacle | 76 |
7.6%
|