| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
1.1%
|
| -7 | Does not apply | 40 |
11.3%
|
| 0 | No obstacle | 115 |
32.5%
|
| 1 | Minor obstacle | 50 |
14.1%
|
| 2 | Moderate obstacle | 60 |
16.9%
|
| 3 | Major obstacle | 52 |
14.7%
|
| 4 | Very severe obstacle | 33 |
9.3%
|