| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 50 |
3.7%
|
| -7 | Does not apply | 131 |
9.8%
|
| 0 | No obstacle | 523 |
39.1%
|
| 1 | Minor obstacle | 161 |
12%
|
| 2 | Moderate obstacle | 169 |
12.6%
|
| 3 | Major obstacle | 162 |
12.1%
|
| 4 | Very severe obstacle | 141 |
10.5%
|