| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 |
1.9%
|
| -7 | Does not apply | 9 |
2.8%
|
| 0 | No obstacle | 105 |
32.8%
|
| 1 | Minor obstacle | 64 |
20%
|
| 2 | Moderate obstacle | 104 |
32.5%
|
| 3 | Major obstacle | 28 |
8.8%
|
| 4 | Very severe obstacle | 4 |
1.3%
|