| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 2 |
0.8%
|
| 0 | No obstacle | 148 |
61.2%
|
| 1 | Minor obstacle | 29 |
12%
|
| 2 | Moderate obstacle | 41 |
16.9%
|
| 3 | Major obstacle | 17 |
7%
|
| 4 | Very severe obstacle | 5 |
2.1%
|