| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 5 |
1.4%
|
| 0 | No obstacle | 119 |
32.7%
|
| 1 | Minor obstacle | 83 |
22.8%
|
| 2 | Moderate obstacle | 87 |
23.9%
|
| 3 | Major obstacle | 55 |
15.1%
|
| 4 | Very severe obstacle | 15 |
4.1%
|