| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
0.7%
|
| -7 | Does not apply | 6 |
0.6%
|
| 0 | No obstacle | 231 |
23.1%
|
| 1 | Minor obstacle | 235 |
23.5%
|
| 2 | Moderate obstacle | 162 |
16.2%
|
| 3 | Major obstacle | 245 |
24.5%
|
| 4 | Very severe obstacle | 115 |
11.5%
|