| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.6%
|
| -7 | Does not apply | 2 |
1.2%
|
| 0 | No obstacle | 74 |
42.8%
|
| 1 | Minor obstacle | 15 |
8.7%
|
| 2 | Moderate obstacle | 20 |
11.6%
|
| 3 | Major obstacle | 25 |
14.5%
|
| 4 | Very severe obstacle | 36 |
20.8%
|