| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | and [prep] a period | 38 |
|
| 2 | and over a period | 14 |
|
| 3 | and over a period | 14 |
|
| 4 | and for a period | 13 |
|
| 5 | and for a period | 13 |
|
| 6 | and after a period | 7 |
|
| 7 | and after a period | 7 |
|
