| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [conj] over a period of time | 14 |
|
| 2 | [conj] over a period [prep] time | 14 |
|
| 3 | [coord] over a period [prep] time | 11 |
|
| 4 | and over a period [prep] time | 7 |
|
| 5 | and over a period [prep] time | 7 |
|
