| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 5 |
1.4%
|
| 0 | No obstacle | 262 |
73.2%
|
| 1 | Minor obstacle | 47 |
13.1%
|
| 2 | Moderate obstacle | 29 |
8.1%
|
| 3 | Major obstacle | 10 |
2.8%
|
| 4 | Very severe obstacle | 5 |
1.4%
|