| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | after a [adj] period of | 68 |
|
| 2 | [vb pp] a [adj] period of | 15 |
|
| 3 | [vb pp] after a [adj] period | 10 |
|
| 4 | [vb pp] after a period of | 5 |
|
