| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 16 |
4.4%
|
| 0 | No obstacle | 269 |
73.9%
|
| 1 | Minor obstacle | 42 |
11.5%
|
| 2 | Moderate obstacle | 23 |
6.3%
|
| 3 | Major obstacle | 7 |
1.9%
|
| 4 | Very severe obstacle | 7 |
1.9%
|