| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply (spontaneous) | 5 |
0.3%
|
| 0 | No obstacle | 1296 |
82.4%
|
| 1 | Minor obstacle | 165 |
10.5%
|
| 2 | Moderate obstacle | 73 |
4.6%
|
| 3 | Major obstacle | 22 |
1.4%
|
| 4 | Very severe obstacle | 12 |
0.8%
|