| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adj] period | 462 |
|
| 2 | [adv] a [adj] period | 136 |
|
| 3 | [adv] over a [adj] | 122 |
|
| 4 | [adv] over a period | 69 |
|
