| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adj] period | 545 |
|
| 2 | [prep] a long period | 391 |
|
| 3 | over a long [noun sg] | 272 |
|
| 4 | over a long [noun] | 272 |
|
| 5 | over [art] long period | 235 |
|
| 6 | over a long period | 232 |
|
