| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 |
1.7%
|
| -7 | Does not apply | 6 |
1.7%
|
| 0 | No obstacle | 121 |
33.4%
|
| 1 | Minor obstacle | 57 |
15.7%
|
| 2 | Moderate obstacle | 75 |
20.7%
|
| 3 | Major obstacle | 63 |
17.4%
|
| 4 | Very severe obstacle | 34 |
9.4%
|