| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 |
2.5%
|
| -7 | Does not apply | 32 |
8.9%
|
| 0 | No obstacle | 214 |
59.6%
|
| 1 | Minor obstacle | 55 |
15.3%
|
| 2 | Moderate obstacle | 31 |
8.6%
|
| 3 | Major obstacle | 12 |
3.3%
|
| 4 | Very severe obstacle | 6 |
1.7%
|