| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a long period | 181 |
|
| 2 | [vb pp] over a period | 78 |
|
| 3 | [vb pp] over a long | 37 |
|
| 4 | [vb pp] over long period | 10 |
|
| 5 | [vb pp] a long period | 7 |
|
