| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.7%
|
| -7 | Does not apply | 16 |
3.9%
|
| 0 | No obstacle | 252 |
61.6%
|
| 1 | Minor obstacle | 61 |
14.9%
|
| 2 | Moderate obstacle | 49 |
12%
|
| 3 | Major obstacle | 19 |
4.6%
|
| 4 | Very severe obstacle | 9 |
2.2%
|