| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adj] over a period [prep] | 28 |
|
| 2 | [adj] over a period of | 27 |
|
| 3 | [adj] over a period of | 27 |
|
| 4 | [adj] over a period [prep] | 19 |
|
