| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] the [num] period | 117 |
|
| 2 | [prep] [art] [num] period | 76 |
|
| 3 | [prep] [art] [num] periods | 43 |
|
| 4 | in [art] [num] period | 32 |
|
| 5 | [prep] [art] two period | 31 |
|
| 6 | during [art] [num] period | 20 |
|
| 7 | of [art] [num] period | 18 |
|
| 8 | for [art] [num] period | 15 |
|
| 9 | between [art] [num] period | 14 |
|
| 10 | over [art] [num] period | 9 |
|
| 11 | [prep] [art] three period | 6 |
|
| 12 | [prep] [art] 1980–9 period | 5 |
|
