| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 86 |
6.4%
|
| -7 | Does not apply | 94 |
7%
|
| 0 | No obstacle | 276 |
20.6%
|
| 1 | Minor obstacle | 247 |
18.5%
|
| 2 | Moderate obstacle | 271 |
20.3%
|
| 3 | Major obstacle | 214 |
16%
|
| 4 | Very severe obstacle | 149 |
11.1%
|