| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 24 |
7.2%
|
| 0 | No obstacle | 197 |
59.3%
|
| 1 | Minor obstacle | 56 |
16.9%
|
| 2 | Moderate obstacle | 30 |
9%
|
| 3 | Major obstacle | 20 |
6%
|
| 4 | Very severe obstacle | 5 |
1.5%
|