| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | place over a period of | 9 |
|
| 2 | place over a period [prep] | 9 |
|
| 3 | place over a period of | 9 |
|
| 4 | place over a period [prep] | 9 |
|
| 5 | [verb] place over a period | 6 |
|
| 6 | take place over a period | 6 |
|
