| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.9%
|
| -7 | Does not apply | 13 |
4.9%
|
| 0 | No obstacle | 150 |
56%
|
| 1 | Minor obstacle | 45 |
16.8%
|
| 2 | Moderate obstacle | 30 |
11.2%
|
| 3 | Major obstacle | 16 |
6%
|
| 4 | Very severe obstacle | 9 |
3.4%
|