| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] over a long period | 34 |
|
| 2 | [vb pp] [adv] over a period | 19 |
|
| 3 | [adv] over a long period | 18 |
|
| 4 | [vb pp] [adv] over a long | 5 |
|
