| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 |
1.3%
|
| -7 | Does not apply | 28 |
4.7%
|
| 0 | No obstacle | 262 |
43.7%
|
| 1 | Minor obstacle | 67 |
11.2%
|
| 2 | Moderate obstacle | 74 |
12.3%
|
| 3 | Major obstacle | 95 |
15.8%
|
| 4 | Very severe obstacle | 66 |
11%
|