| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 |
1.1%
|
| -7 | Does not apply | 62 |
8.7%
|
| 0 | No obstacle | 266 |
37.5%
|
| 1 | Minor obstacle | 136 |
19.2%
|
| 2 | Moderate obstacle | 119 |
16.8%
|
| 3 | Major obstacle | 70 |
9.9%
|
| 4 | Very severe obstacle | 49 |
6.9%
|