| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 17 |
4.8%
|
| 0 | No obstacle | 161 |
45.6%
|
| 1 | Minor obstacle | 43 |
12.2%
|
| 2 | Moderate obstacle | 85 |
24.1%
|
| 3 | Major obstacle | 36 |
10.2%
|
| 4 | Very severe obstacle | 8 |
2.3%
|