| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 |
3.4%
|
| -7 | Does not apply | 33 |
9.4%
|
| 0 | No obstacle | 144 |
40.9%
|
| 1 | Minor obstacle | 62 |
17.6%
|
| 2 | Moderate obstacle | 42 |
11.9%
|
| 3 | Major obstacle | 23 |
6.5%
|
| 4 | Very severe obstacle | 36 |
10.2%
|