| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.4%
|
| -7 | Does not apply | 9 |
2.5%
|
| 0 | No obstacle | 169 |
46.9%
|
| 1 | Minor obstacle | 56 |
15.6%
|
| 2 | Moderate obstacle | 63 |
17.5%
|
| 3 | Major obstacle | 32 |
8.9%
|
| 4 | Very severe obstacle | 26 |
7.2%
|