| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.4%
|
| -7 | Does not apply | 18 |
3.6%
|
| 0 | No obstacle | 243 |
48.4%
|
| 1 | Minor obstacle | 94 |
18.7%
|
| 2 | Moderate obstacle | 100 |
19.9%
|
| 3 | Major obstacle | 33 |
6.6%
|
| 4 | Very severe obstacle | 12 |
2.4%
|