| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 116 |
7%
|
| -7 | Does not apply | 371 |
22.3%
|
| 0 | No obstacle | 429 |
25.8%
|
| 1 | Minor obstacle | 135 |
8.1%
|
| 2 | Moderate obstacle | 254 |
15.3%
|
| 3 | Major obstacle | 225 |
13.5%
|
| 4 | Very severe obstacle | 133 |
8%
|