| Value | Category | Cases | |
|---|---|---|---|
| 0 | 0. No difficulty | 4119 |
58.4%
|
| 1 | 1. Minor difficulty | 2676 |
37.9%
|
| 2 | 2. Big difficulty | 105 |
1.5%
|
| 3 | 3. Not applicable | 157 |
2.2%
|