| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
1.7%
|
| -7 | Does not apply | 10 |
4.2%
|
| 0 | No obstacle | 130 |
54.2%
|
| 1 | Minor obstacle | 28 |
11.7%
|
| 2 | Moderate obstacle | 25 |
10.4%
|
| 3 | Major obstacle | 30 |
12.5%
|
| 4 | Very severe obstacle | 13 |
5.4%
|