| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [art] [adj] period [prep] | 1473 |
|
| 2 | [prep] [art] [adj] year [prep] | 987 |
|
| 3 | [prep] [art] [adj] year period | 173 |
|
| 4 | [art] [adj] year period [prep] | 40 |
|
