| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adj] period [conj] | 28 |
|
| 2 | over a [adj] period [conj] | 22 |
|
| 3 | over a long period [conj] | 16 |
|
| 4 | over a long period [conj] | 10 |
|
| 5 | over a [adj -er] period [conj] | 6 |
|
| 6 | over a longer period [conj] | 6 |
|
