| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 33 |
2.7%
|
| -7 | Does not apply | 20 |
1.6%
|
| 0 | No obstacle | 795 |
64.2%
|
| 1 | Minor obstacle | 136 |
11%
|
| 2 | Moderate obstacle | 131 |
10.6%
|
| 3 | Major obstacle | 61 |
4.9%
|
| 4 | Very severe obstacle | 63 |
5.1%
|