| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 |
1.2%
|
| -7 | Does not apply | 32 |
4.2%
|
| 0 | No obstacle | 241 |
31.7%
|
| 1 | Minor obstacle | 123 |
16.2%
|
| 2 | Moderate obstacle | 212 |
27.9%
|
| 3 | Major obstacle | 73 |
9.6%
|
| 4 | Very severe obstacle | 70 |
9.2%
|