| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
1.9%
|
| -7 | Does not apply | 5 |
1.4%
|
| 0 | No obstacle | 94 |
25.8%
|
| 1 | Minor obstacle | 120 |
32.9%
|
| 2 | Moderate obstacle | 85 |
23.3%
|
| 3 | Major obstacle | 37 |
10.1%
|
| 4 | Very severe obstacle | 17 |
4.7%
|