| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period of | 618 |
|
| 2 | [prep] a [adj] period of | 618 |
|
| 3 | over a [adj] [noun] of | 383 |
|
| 4 | over a [adj] period [prep] | 183 |
|
| 5 | over a [adj] period [prep] | 183 |
|
| 6 | over [art] [adj] period of | 162 |
|
| 7 | over a [adj] period of | 143 |
|
| 8 | over a [adj] period of | 143 |
|
