| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 15 |
4.3%
|
| -7 | Does not apply | 31 |
8.8%
|
| 0 | No obstacle | 115 |
32.7%
|
| 1 | Minor obstacle | 59 |
16.8%
|
| 2 | Moderate obstacle | 57 |
16.2%
|
| 3 | Major obstacle | 34 |
9.7%
|
| 4 | Very severe obstacle | 41 |
11.6%
|