| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 4 |
1.5%
|
| 0 | No obstacle | 117 |
45.2%
|
| 1 | Minor obstacle | 35 |
13.5%
|
| 2 | Moderate obstacle | 51 |
19.7%
|
| 3 | Major obstacle | 33 |
12.7%
|
| 4 | Very severe obstacle | 19 |
7.3%
|