| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 32 |
8.9%
|
| 0 | No obstacle | 178 |
49.4%
|
| 1 | Minor obstacle | 40 |
11.1%
|
| 2 | Moderate obstacle | 64 |
17.8%
|
| 3 | Major obstacle | 28 |
7.8%
|
| 4 | Very severe obstacle | 15 |
4.2%
|