| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 4 |
1.2%
|
| 0 | No obstacle | 197 |
59.3%
|
| 1 | Minor obstacle | 63 |
19%
|
| 2 | Moderate obstacle | 34 |
10.2%
|
| 3 | Major obstacle | 27 |
8.1%
|
| 4 | Very severe obstacle | 7 |
2.1%
|