| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
1.2%
|
| -7 | Does not apply | 36 |
6%
|
| 0 | No obstacle | 356 |
59.5%
|
| 1 | Minor obstacle | 124 |
20.7%
|
| 2 | Moderate obstacle | 35 |
5.9%
|
| 3 | Major obstacle | 30 |
5%
|
| 4 | Very severe obstacle | 10 |
1.7%
|