| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 129 |
7.8%
|
| -7 | Does not apply | 500 |
30.1%
|
| 0 | No obstacle | 442 |
26.6%
|
| 1 | Minor obstacle | 109 |
6.6%
|
| 2 | Moderate obstacle | 179 |
10.8%
|
| 3 | Major obstacle | 197 |
11.8%
|
| 4 | Very severe obstacle | 107 |
6.4%
|