| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] over a period of | 289 |
|
| 2 | [conj] over a period of | 25 |
|
| 3 | [noun] [conj] a period of | 18 |
|
| 4 | [noun] [conj] over a period | 8 |
|
