| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 49 |
31.6%
|
| 1 | Minor obstacle | 35 |
22.6%
|
| 2 | Moderate obstacle | 27 |
17.4%
|
| 3 | Major obstacle | 25 |
16.1%
|
| 4 | Very severe obstacle | 19 |
12.3%
|