| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 46 |
7.7%
|
| -7 | Does not apply | 35 |
5.9%
|
| 0 | No obstacle | 387 |
64.7%
|
| 1 | Minor obstacle | 102 |
17.1%
|
| 2 | Moderate obstacle | 16 |
2.7%
|
| 3 | Major obstacle | 7 |
1.2%
|
| 4 | Very severe obstacle | 5 |
0.8%
|