| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.2%
|
| -7 | Does not apply | 71 |
17.7%
|
| 0 | No obstacle | 161 |
40%
|
| 1 | Minor obstacle | 55 |
13.7%
|
| 2 | Moderate obstacle | 46 |
11.4%
|
| 3 | Major obstacle | 26 |
6.5%
|
| 4 | Very severe obstacle | 38 |
9.5%
|