| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
1%
|
| -7 | Does not apply | 5 |
4.9%
|
| 0 | No obstacle | 42 |
40.8%
|
| 1 | Minor obstacle | 22 |
21.4%
|
| 2 | Moderate obstacle | 12 |
11.7%
|
| 3 | Major obstacle | 15 |
14.6%
|
| 4 | Very severe obstacle | 6 |
5.8%
|