| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [noun] | 2678 |
|
| 2 | over a [noun sg] | 2604 |
|
| 3 | [prep] a period | 2139 |
|
| 4 | [prep] a period | 2139 |
|
| 5 | over [art] period | 991 |
|
| 6 | over a period | 682 |
|
| 7 | over a period | 682 |
|
