| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 24 |
1.8%
|
| -7 | Does not apply | 37 |
2.8%
|
| 0 | No obstacle | 643 |
48.6%
|
| 1 | Minor obstacle | 324 |
24.5%
|
| 2 | Moderate obstacle | 238 |
18%
|
| 3 | Major obstacle | 46 |
3.5%
|
| 4 | Very severe obstacle | 11 |
0.8%
|