| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.4%
|
| -7 | Does not apply | 23 |
9.9%
|
| 0 | No obstacle | 147 |
63.1%
|
| 1 | Minor obstacle | 6 |
2.6%
|
| 2 | Moderate obstacle | 30 |
12.9%
|
| 3 | Major obstacle | 21 |
9%
|
| 4 | Very severe obstacle | 5 |
2.1%
|