| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 11 |
0.9%
|
| -7 | Does not apply | 4 |
0.3%
|
| 0 | No obstacle | 656 |
52.9%
|
| 1 | Minor obstacle | 164 |
13.2%
|
| 2 | Moderate obstacle | 156 |
12.6%
|
| 3 | Major obstacle | 85 |
6.9%
|
| 4 | Very severe obstacle | 163 |
13.2%
|