| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 14 |
1.4%
|
| -7 | Does not apply | 20 |
2%
|
| 0 | No obstacle | 211 |
20.7%
|
| 1 | Minor obstacle | 162 |
15.9%
|
| 2 | Moderate obstacle | 234 |
23%
|
| 3 | Major obstacle | 238 |
23.4%
|
| 4 | Very severe obstacle | 140 |
13.7%
|