| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [vb pp] over a period | 46 |
|
| 2 | be [vb pp] over a period | 16 |
|
| 3 | [be] [vb pp] over a period | 16 |
|
| 4 | [was/were] [vb pp] over a period | 15 |
|
| 5 | was [vb pp] over a period | 11 |
|
| 6 | [is] [vb pp] over a period | 6 |
|
| 7 | is [vb pp] over a period | 6 |
|
| 8 | [be] made over a period | 5 |
|
