| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 15 |
1.5%
|
| -7 | Does not apply | 97 |
9.7%
|
| 0 | No obstacle | 803 |
80.5%
|
| 1 | Minor obstacle | 54 |
5.4%
|
| 2 | Moderate obstacle | 20 |
2%
|
| 3 | Major obstacle | 7 |
0.7%
|
| 4 | Very severe obstacle | 2 |
0.2%
|