| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.4%
|
| -7 | Does not apply | 15 |
4.2%
|
| 0 | No obstacle | 145 |
40.3%
|
| 1 | Minor obstacle | 44 |
12.2%
|
| 2 | Moderate obstacle | 62 |
17.2%
|
| 3 | Major obstacle | 48 |
13.3%
|
| 4 | Very severe obstacle | 41 |
11.4%
|