| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 399 |
30.7%
|
| 1 | Minor obstacle | 400 |
30.8%
|
| 2 | Moderate obstacle | 250 |
19.2%
|
| 3 | Major obstacle | 146 |
11.2%
|
| 4 | Very severe obstacle | 105 |
8.1%
|