| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 |
1%
|
| -7 | Does not apply | 11 |
1.9%
|
| 0 | No obstacle | 369 |
62.3%
|
| 1 | Minor obstacle | 67 |
11.3%
|
| 2 | Moderate obstacle | 56 |
9.5%
|
| 3 | Major obstacle | 64 |
10.8%
|
| 4 | Very severe obstacle | 19 |
3.2%
|