| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
0.7%
|
| -7 | Does not apply | 3 |
0.4%
|
| 0 | No obstacle | 386 |
54.1%
|
| 1 | Minor obstacle | 162 |
22.7%
|
| 2 | Moderate obstacle | 93 |
13%
|
| 3 | Major obstacle | 41 |
5.8%
|
| 4 | Very severe obstacle | 23 |
3.2%
|