| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.6%
|
| -7 | Does not apply | 3 |
0.8%
|
| 0 | No obstacle | 63 |
17.8%
|
| 1 | Minor obstacle | 38 |
10.7%
|
| 2 | Moderate obstacle | 107 |
30.2%
|
| 3 | Major obstacle | 92 |
26%
|
| 4 | Very severe obstacle | 49 |
13.8%
|