| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun sg] over a [adj] period of | 50 |
|
| 2 | [noun sg] over a long period of | 36 |
|
| 3 | [noun sg] over a long period of | 32 |
|
| 4 | [noun sg] over a [adj -er] period of | 5 |
|
