| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] over a period of | 59 |
|
| 2 | occur over [art] period of | 6 |
|
| 3 | occur over [art] period of | 6 |
|
| 4 | occur over a [noun sg] of | 5 |
|
| 5 | occur over a period of | 5 |
|
| 6 | occur over a period of | 5 |
|
| 7 | occur [adv prt] a period of | 5 |
|
| 8 | occur [adv] a period of | 5 |
|
| 9 | occur over a period of | 5 |
|
| 10 | occur over a period [prep] | 5 |
|
| 11 | occur over a [noun] of | 5 |
|
| 12 | occur over a period [prep] | 5 |
|
| 13 | occur over a period of | 5 |
|
