| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.2%
|
| -7 | Does not apply | 6 |
1.2%
|
| 0 | No obstacle | 199 |
38.9%
|
| 1 | Minor obstacle | 171 |
33.5%
|
| 2 | Moderate obstacle | 65 |
12.7%
|
| 3 | Major obstacle | 50 |
9.8%
|
| 4 | Very severe obstacle | 19 |
3.7%
|