| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 202 |
42.6%
|
| 1 | Minor obstacle | 110 |
23.2%
|
| 2 | Moderate obstacle | 83 |
17.5%
|
| 3 | Major obstacle | 44 |
9.3%
|
| 4 | Very severe obstacle | 35 |
7.4%
|