| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
1.9%
|
| -7 | Does not apply | 1 |
0.3%
|
| 0 | No obstacle | 65 |
18%
|
| 1 | Minor obstacle | 49 |
13.5%
|
| 2 | Moderate obstacle | 113 |
31.2%
|
| 3 | Major obstacle | 74 |
20.4%
|
| 4 | Very severe obstacle | 53 |
14.6%
|