| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.7%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 99 |
32.2%
|
| 1 | Minor obstacle | 101 |
32.9%
|
| 2 | Moderate obstacle | 55 |
17.9%
|
| 3 | Major obstacle | 41 |
13.4%
|
| 4 | Very severe obstacle | 9 |
2.9%
|