| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 54 |
19.9%
|
| -7 | Does not apply | 2 |
0.7%
|
| 0 | No obstacle | 26 |
9.6%
|
| 1 | Minor obstacle | 22 |
8.1%
|
| 2 | Moderate obstacle | 47 |
17.3%
|
| 3 | Major obstacle | 69 |
25.5%
|
| 4 | Very severe obstacle | 51 |
18.8%
|