| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] over a [adj] period | 73 |
|
| 2 | [vb pp] over a [adj] period | 72 |
|
| 3 | [verb] over a long period | 35 |
|
| 4 | develop over a [adj] period | 5 |
|
| 5 | developed over a [adj] period | 5 |
|
| 6 | [verb] over a three-year period | 5 |
|
