| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 |
2%
|
| -7 | Does not apply | 61 |
10.2%
|
| 0 | No obstacle | 403 |
67.4%
|
| 1 | Minor obstacle | 77 |
12.9%
|
| 2 | Moderate obstacle | 26 |
4.3%
|
| 3 | Major obstacle | 10 |
1.7%
|
| 4 | Very severe obstacle | 9 |
1.5%
|