| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 125 |
31.1%
|
| 1 | Minor obstacle | 88 |
21.9%
|
| 2 | Moderate obstacle | 114 |
28.4%
|
| 3 | Major obstacle | 45 |
11.2%
|
| 4 | Very severe obstacle | 30 |
7.5%
|