| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 48 |
3.6%
|
| -7 | Does not apply | 174 |
13.2%
|
| 0 | No obstacle | 643 |
48.6%
|
| 1 | Minor obstacle | 240 |
18.1%
|
| 2 | Moderate obstacle | 155 |
11.7%
|
| 3 | Major obstacle | 41 |
3.1%
|
| 4 | Very severe obstacle | 22 |
1.7%
|