| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adj] period | 545 |
|
| 2 | [noun pl] over a [adj] | 326 |
|
| 3 | [noun pl] over a period | 109 |
|
| 4 | [noun pl] over [adj] period | 17 |
|
