| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 34 |
5.6%
|
| 0 | No obstacle | 238 |
38.9%
|
| 1 | Minor obstacle | 113 |
18.5%
|
| 2 | Moderate obstacle | 90 |
14.7%
|
| 3 | Major obstacle | 75 |
12.3%
|
| 4 | Very severe obstacle | 62 |
10.1%
|