| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.3%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 221 |
61.6%
|
| 1 | Minor obstacle | 35 |
9.7%
|
| 2 | Moderate obstacle | 31 |
8.6%
|
| 3 | Major obstacle | 27 |
7.5%
|
| 4 | Very severe obstacle | 44 |
12.3%
|