| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 29 |
8.2%
|
| 0 | No obstacle | 176 |
49.9%
|
| 1 | Minor obstacle | 56 |
15.9%
|
| 2 | Moderate obstacle | 51 |
14.4%
|
| 3 | Major obstacle | 32 |
9.1%
|
| 4 | Very severe obstacle | 9 |
2.5%
|