| Value | Category | Cases | |
|---|---|---|---|
| 0 | Not one of the three most important sources | 83 |
84.7%
|
| 1 | First rank | 1 |
1%
|
| 2 | Second rank | 10 |
10.2%
|
| 3 | Third rank | 4 |
4.1%
|
| -9 | 5 | ||
| -7 | 30 |