| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 53 |
4.8%
|
| -7 | Does not apply | 37 |
3.4%
|
| 0 | No obstacle | 106 |
9.7%
|
| 1 | Minor obstacle | 243 |
22.2%
|
| 2 | Moderate obstacle | 397 |
36.2%
|
| 3 | Major obstacle | 216 |
19.7%
|
| 4 | Very severe obstacle | 44 |
4%
|