| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 13 |
1.8%
|
| -7 | Does not apply | 43 |
5.9%
|
| 0 | No obstacle | 295 |
40.8%
|
| 1 | Minor obstacle | 129 |
17.8%
|
| 2 | Moderate obstacle | 103 |
14.2%
|
| 3 | Major obstacle | 79 |
10.9%
|
| 4 | Very severe obstacle | 61 |
8.4%
|