| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 25 |
1.9%
|
| -7 | Does not apply | 153 |
11.4%
|
| 0 | No obstacle | 476 |
35.6%
|
| 1 | Minor obstacle | 164 |
12.3%
|
| 2 | Moderate obstacle | 216 |
16.2%
|
| 3 | Major obstacle | 172 |
12.9%
|
| 4 | Very severe obstacle | 131 |
9.8%
|