| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.8%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 54 |
45%
|
| 1 | Minor obstacle | 18 |
15%
|
| 2 | Moderate obstacle | 23 |
19.2%
|
| 3 | Major obstacle | 8 |
6.7%
|
| 4 | Very severe obstacle | 16 |
13.3%
|