| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] [prep] a period of | 215 |
|
| 2 | [vb pp] over a [noun] of | 150 |
|
| 3 | [vb pp] over [art] period of | 76 |
|
| 4 | [vb pp] over [art] period of | 76 |
|
| 5 | [verb] over a period of | 75 |
|
| 6 | [vb pp] over a period [prep] | 71 |
|
| 7 | [vb pp] over a period [prep] | 71 |
|
| 8 | [vb pp] over a period of | 70 |
|
| 9 | [vb pp] over a period of | 70 |
|
