| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [num] year period [prep] | 11 |
|
| 2 | over a [num] year period [prep] | 11 |
|
| 3 | [noun] over a [num] year period | 43 |
|
| 4 | [noun sg] over a [num] year period | 21 |
|
| 5 | [noun pl] over a [num] year period | 17 |
|
| 6 | [vb pp] over a [num] year period | 8 |
|
| 7 | [verb] over a [num] year period | 8 |
|
