| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.2%
|
| -7 | Does not apply | 18 |
4.5%
|
| 0 | No obstacle | 236 |
58.7%
|
| 1 | Minor obstacle | 69 |
17.2%
|
| 2 | Moderate obstacle | 42 |
10.4%
|
| 3 | Major obstacle | 24 |
6%
|
| 4 | Very severe obstacle | 8 |
2%
|