| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.4%
|
| -7 | Does not apply | 6 |
2.6%
|
| 0 | No obstacle | 128 |
54.9%
|
| 1 | Minor obstacle | 33 |
14.2%
|
| 2 | Moderate obstacle | 13 |
5.6%
|
| 3 | Major obstacle | 41 |
17.6%
|
| 4 | Very severe obstacle | 11 |
4.7%
|