| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 47 |
7.9%
|
| 1 | Minor obstacle | 45 |
7.5%
|
| 2 | Moderate obstacle | 105 |
17.6%
|
| 3 | Major obstacle | 191 |
31.9%
|
| 4 | Very severe obstacle | 210 |
35.1%
|