| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
1.7%
|
| -7 | Does not apply | 3 |
2.5%
|
| 0 | No obstacle | 52 |
43.3%
|
| 1 | Minor obstacle | 6 |
5%
|
| 2 | Moderate obstacle | 30 |
25%
|
| 3 | Major obstacle | 18 |
15%
|
| 4 | Very severe obstacle | 9 |
7.5%
|