| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 177 |
6%
|
| -7 | Does not apply | 339 |
11.5%
|
| 0 | No obstacle | 1334 |
45.1%
|
| 1 | Minor obstacle | 498 |
16.9%
|
| 2 | Moderate obstacle | 433 |
14.7%
|
| 3 | Major obstacle | 146 |
4.9%
|
| 4 | Very severe obstacle | 28 |
0.9%
|