| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 21 |
1.6%
|
| -7 | Does not apply | 35 |
2.6%
|
| 0 | No obstacle | 715 |
54%
|
| 1 | Minor obstacle | 261 |
19.7%
|
| 2 | Moderate obstacle | 133 |
10.1%
|
| 3 | Major obstacle | 61 |
4.6%
|
| 4 | Very severe obstacle | 97 |
7.3%
|