| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] over a period [prep] a | 18 |
|
| 2 | [noun] over a period of [art] | 18 |
|
| 3 | [noun sg] over a period [prep] [art] | 11 |
|
| 4 | [noun pl] over a period [prep] [art] | 8 |
|
