| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.4%
|
| -7 | Does not apply | 19 |
5.3%
|
| 0 | No obstacle | 153 |
42.6%
|
| 1 | Minor obstacle | 67 |
18.7%
|
| 2 | Moderate obstacle | 56 |
15.6%
|
| 3 | Major obstacle | 33 |
9.2%
|
| 4 | Very severe obstacle | 26 |
7.2%
|