| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] over a [adj] period | 84 |
|
| 2 | [vb pp] [prep] a long period | 67 |
|
| 3 | [vb pp] [prep] a long period | 67 |
|
| 4 | [vb pp] over a long [noun] | 47 |
|
| 5 | [verb] over a long period | 46 |
|
| 6 | [vb pp] over a long period | 44 |
|
| 7 | [vb pp] over [art] long period | 44 |
|
