| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 20 |
7.4%
|
| -7 | Does not apply | 2 |
0.7%
|
| 0 | No obstacle | 54 |
19.9%
|
| 1 | Minor obstacle | 42 |
15.5%
|
| 2 | Moderate obstacle | 59 |
21.8%
|
| 3 | Major obstacle | 67 |
24.7%
|
| 4 | Very severe obstacle | 27 |
10%
|