| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.4%
|
| 0 | No obstacle | 181 |
69.9%
|
| 1 | Minor obstacle | 30 |
11.6%
|
| 2 | Moderate obstacle | 26 |
10%
|
| 3 | Major obstacle | 10 |
3.9%
|
| 4 | Very severe obstacle | 11 |
4.2%
|