| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
1.4%
|
| -7 | Does not apply | 1 |
0.7%
|
| 0 | No obstacle | 63 |
43.4%
|
| 1 | Minor obstacle | 24 |
16.6%
|
| 2 | Moderate obstacle | 29 |
20%
|
| 3 | Major obstacle | 19 |
13.1%
|
| 4 | Very severe obstacle | 7 |
4.8%
|