| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a period of | 1599 |
|
| 2 | [prep] a period of | 1599 |
|
| 3 | over a period of | 617 |
|
| 4 | over a period of | 617 |
|
| 5 | for a period of | 339 |
|
| 6 | for a period of | 339 |
|
| 7 | after a period of | 128 |
|
| 8 | after a period of | 128 |
|
| 9 | in a period of | 119 |
|
| 10 | in a period of | 119 |
|
| 11 | during a period of | 72 |
|
| 12 | during a period of | 72 |
|
| 13 | within a period of | 47 |
|
| 14 | within a period of | 47 |
|
| 15 | through a period of | 46 |
|
| 16 | through a period of | 46 |
|
| 17 | of a period of | 44 |
|
| 18 | of a period of | 44 |
|
| 19 | with a period of | 40 |
|
| 20 | with a period of | 40 |
|
| 21 | by a period of | 33 |
|
| 22 | by a period of | 33 |
|
| 23 | to a period of | 32 |
|
| 24 | to a period of | 32 |
|
| 25 | as a period of | 31 |
|
| 26 | as a period of | 31 |
|
| 27 | from a period of | 16 |
|
| 28 | from a period of | 16 |
|
| 29 | on a period of | 8 |
|
| 30 | into a period of | 8 |
|
