| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.2%
|
| -7 | Does not apply | 52 |
12.9%
|
| 0 | No obstacle | 195 |
48.5%
|
| 1 | Minor obstacle | 81 |
20.1%
|
| 2 | Moderate obstacle | 41 |
10.2%
|
| 3 | Major obstacle | 18 |
4.5%
|
| 4 | Very severe obstacle | 10 |
2.5%
|