| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 15 |
3.7%
|
| -7 | Does not apply | 19 |
4.6%
|
| 0 | No obstacle | 256 |
62.6%
|
| 1 | Minor obstacle | 53 |
13%
|
| 2 | Moderate obstacle | 32 |
7.8%
|
| 3 | Major obstacle | 29 |
7.1%
|
| 4 | Very severe obstacle | 5 |
1.2%
|