| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.2%
|
| -7 | Does not apply | 40 |
9.3%
|
| 0 | No obstacle | 188 |
43.7%
|
| 1 | Minor obstacle | 76 |
17.7%
|
| 2 | Moderate obstacle | 82 |
19.1%
|
| 3 | Major obstacle | 31 |
7.2%
|
| 4 | Very severe obstacle | 8 |
1.9%
|