| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period of [noun] | 390 |
|
| 2 | [prep] a [adj] period of [noun] | 390 |
|
| 3 | over a [adj] [noun] of [noun] | 271 |
|
| 4 | over a [adj] period [prep] [noun] | 139 |
|
| 5 | over a [adj] period [prep] [noun] | 139 |
|
| 6 | over a [adj] period of [noun] | 130 |
|
| 7 | over [art] [adj] period of [noun] | 125 |
|
| 8 | over a [adj] period of [noun] | 123 |
|
| 9 | over a [adj] period of [noun] | 123 |
|
