| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] [adv] a [adj] period | 18 |
|
| 2 | [vb past] [adv prt] a [adj] period | 17 |
|
| 3 | [vb past] over a [adj] period | 15 |
|
| 4 | [vb past] over a [adj] period | 15 |
|
| 5 | [vb past] [adv] a long period | 8 |
|
| 6 | [vb past] [adv] a long period | 8 |
|
