| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 28 |
2.7%
|
| -7 | Does not apply | 131 |
12.7%
|
| 0 | No obstacle | 715 |
69.6%
|
| 1 | Minor obstacle | 85 |
8.3%
|
| 2 | Moderate obstacle | 51 |
5%
|
| 3 | Major obstacle | 16 |
1.6%
|
| 4 | Very severe obstacle | 2 |
0.2%
|