| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a period of time [art] | 7 |
|
| 2 | over a period [prep] time [art] | 7 |
|
| 3 | over a period [prep] time [art] | 7 |
|
| 4 | over a period [prep] time the | 6 |
|
| 5 | over a period [prep] time the | 6 |
|
