| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [vb pp] [adv] over a period | 12 |
|
| 2 | be [vb pp] [adv] over a period | 12 |
|
| 3 | [be] [vb pp] [adv] over a period | 7 |
|
| 4 | be [vb pp] [adv] over a period | 7 |
|
| 5 | [vb pp] [adv] over a [adj] period | 18 |
|
| 6 | [vb pp] [adv] over a [adj] period | 16 |
|
| 7 | [vb pp] [adv] over a long period | 7 |
|
| 8 | [vb pp] [adv] over a long period | 5 |
|
| 9 | [vb pp] [adv] over a period of | 16 |
|
| 10 | [vb pp] [adv] over a period [prep] | 16 |
|
| 11 | [vb pp] [adv] over a period [prep] | 16 |
|
| 12 | [vb pp] [adv] over a period of | 16 |
|
