| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
0.7%
|
| -7 | Does not apply | 2 |
0.2%
|
| 0 | No obstacle | 253 |
25.3%
|
| 1 | Minor obstacle | 260 |
26%
|
| 2 | Moderate obstacle | 242 |
24.2%
|
| 3 | Major obstacle | 201 |
20.1%
|
| 4 | Very severe obstacle | 36 |
3.6%
|