| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 29 |
2.6%
|
| -7 | Does not apply | 41 |
3.7%
|
| 0 | No obstacle | 143 |
13%
|
| 1 | Minor obstacle | 251 |
22.9%
|
| 2 | Moderate obstacle | 351 |
32%
|
| 3 | Major obstacle | 229 |
20.9%
|
| 4 | Very severe obstacle | 52 |
4.7%
|