| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
2.1%
|
| -7 | Does not apply | 9 |
3.7%
|
| 0 | No obstacle | 126 |
52.3%
|
| 1 | Minor obstacle | 46 |
19.1%
|
| 2 | Moderate obstacle | 33 |
13.7%
|
| 3 | Major obstacle | 15 |
6.2%
|
| 4 | Very severe obstacle | 7 |
2.9%
|