| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
2.1%
|
| -7 | Does not apply | 8 |
3.4%
|
| 0 | No obstacle | 120 |
51.5%
|
| 1 | Minor obstacle | 43 |
18.5%
|
| 2 | Moderate obstacle | 27 |
11.6%
|
| 3 | Major obstacle | 25 |
10.7%
|
| 4 | Very severe obstacle | 5 |
2.1%
|