| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 5 |
0.8%
|
| 0 | No obstacle | 195 |
31.7%
|
| 1 | Minor obstacle | 130 |
21.1%
|
| 2 | Moderate obstacle | 129 |
21%
|
| 3 | Major obstacle | 111 |
18%
|
| 4 | Very severe obstacle | 45 |
7.3%
|