| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 |
0.8%
|
| -7 | Does not apply | 7 |
0.9%
|
| 0 | No obstacle | 84 |
11.1%
|
| 1 | Minor obstacle | 150 |
19.7%
|
| 2 | Moderate obstacle | 293 |
38.6%
|
| 3 | Major obstacle | 127 |
16.7%
|
| 4 | Very severe obstacle | 93 |
12.2%
|