| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adj] period | 519 |
|
| 2 | [prep] a prolonged period | 42 |
|
| 3 | [prep] a prolonged period | 42 |
|
| 4 | over a prolonged period | 15 |
|
| 5 | over a prolonged [noun] | 15 |
|
| 6 | over [art] prolonged period | 15 |
|
| 7 | over a prolonged period | 15 |
|
| 8 | over [art] prolonged period | 15 |
|
