| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adj] period [prep] | 19 |
|
| 2 | over a [adj] period [prep] | 19 |
|
| 3 | over a [adj] period of | 16 |
|
| 4 | over a long period [prep] | 9 |
|
| 5 | over a long period [prep] | 9 |
|
