| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 41 |
11.5%
|
| 0 | No obstacle | 239 |
66.8%
|
| 1 | Minor obstacle | 20 |
5.6%
|
| 2 | Moderate obstacle | 15 |
4.2%
|
| 3 | Major obstacle | 12 |
3.4%
|
| 4 | Very severe obstacle | 28 |
7.8%
|