| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 21 |
2.1%
|
| -7 | Does not apply | 14 |
1.4%
|
| 0 | No obstacle | 321 |
31.7%
|
| 1 | Minor obstacle | 247 |
24.4%
|
| 2 | Moderate obstacle | 258 |
25.5%
|
| 3 | Major obstacle | 120 |
11.8%
|
| 4 | Very severe obstacle | 32 |
3.2%
|