| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 26 |
1.5%
|
| -7 | Does not apply | 157 |
9.1%
|
| 0 | No obstacle | 702 |
40.7%
|
| 1 | Minor obstacle | 288 |
16.7%
|
| 2 | Moderate obstacle | 210 |
12.2%
|
| 3 | Major obstacle | 205 |
11.9%
|
| 4 | Very severe obstacle | 137 |
7.9%
|