| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.6%
|
| -7 | Does not apply | 2 |
0.7%
|
| 0 | No obstacle | 134 |
43.6%
|
| 1 | Minor obstacle | 55 |
17.9%
|
| 2 | Moderate obstacle | 30 |
9.8%
|
| 3 | Major obstacle | 46 |
15%
|
| 4 | Very severe obstacle | 35 |
11.4%
|