| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adj] period [prep] time | 18 |
|
| 2 | over a [adj] period [prep] time | 18 |
|
| 3 | over a [adj] period of time | 18 |
|
| 4 | over a [adj] period [prep] time | 18 |
|
| 5 | over a [adj] period [prep] time | 16 |
|
| 6 | over a long period [prep] time | 8 |
|
| 7 | over a long period [prep] time | 8 |
|
