| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [coord] [prep] a period of | 32 |
|
| 2 | [coord] [prep] a period of | 32 |
|
| 3 | [coord] over a [noun] of | 29 |
|
| 4 | [conj] over a period of | 25 |
|
| 5 | [coord] over [art] period of | 18 |
|
| 6 | [coord] over a period of | 18 |
|
| 7 | [coord] over a period [prep] | 18 |
|
