| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 |
2.5%
|
| -7 | Does not apply | 27 |
7.5%
|
| 0 | No obstacle | 212 |
59.1%
|
| 1 | Minor obstacle | 39 |
10.9%
|
| 2 | Moderate obstacle | 25 |
7%
|
| 3 | Major obstacle | 29 |
8.1%
|
| 4 | Very severe obstacle | 18 |
5%
|