| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.3%
|
| 0 | No obstacle | 201 |
56.1%
|
| 1 | Minor obstacle | 68 |
19%
|
| 2 | Moderate obstacle | 59 |
16.5%
|
| 3 | Major obstacle | 20 |
5.6%
|
| 4 | Very severe obstacle | 9 |
2.5%
|