| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 14 |
1%
|
| -7 | Does not apply | 41 |
2.9%
|
| 0 | No obstacle | 500 |
34.9%
|
| 1 | Minor obstacle | 256 |
17.9%
|
| 2 | Moderate obstacle | 241 |
16.8%
|
| 3 | Major obstacle | 223 |
15.6%
|
| 4 | Very severe obstacle | 157 |
11%
|