| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 6 |
5.3%
|
| 0 | No obstacle | 56 |
49.1%
|
| 1 | Minor obstacle | 24 |
21.1%
|
| 2 | Moderate obstacle | 15 |
13.2%
|
| 3 | Major obstacle | 10 |
8.8%
|
| 4 | Very severe obstacle | 3 |
2.6%
|