| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 47 |
13.2%
|
| 0 | No obstacle | 59 |
16.5%
|
| 1 | Minor obstacle | 58 |
16.2%
|
| 2 | Moderate obstacle | 99 |
27.7%
|
| 3 | Major obstacle | 66 |
18.5%
|
| 4 | Very severe obstacle | 25 |
7%
|