| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
0.7%
|
| -7 | Does not apply | 7 |
0.9%
|
| 0 | No obstacle | 87 |
11.4%
|
| 1 | Minor obstacle | 172 |
22.6%
|
| 2 | Moderate obstacle | 302 |
39.7%
|
| 3 | Major obstacle | 105 |
13.8%
|
| 4 | Very severe obstacle | 82 |
10.8%
|