| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adj] period | 462 |
|
| 2 | over a long period | 181 |
|
| 3 | over a five-year period | 25 |
|
| 4 | over a three-year period | 24 |
|
| 5 | over a two-year period | 15 |
|
| 6 | over a prolonged period | 15 |
|
| 7 | over a short period | 14 |
|
| 8 | over a given period | 12 |
|
| 9 | over a four-year period | 8 |
|
| 10 | over a 10-year period | 8 |
|
| 11 | over a 24-hour period | 7 |
|
| 12 | over a considerable period | 7 |
|
| 13 | over a six-month period | 7 |
|
| 14 | over a lengthy period | 7 |
|
| 15 | over a six-year period | 6 |
|
| 16 | over a seven-year period | 5 |
|
| 17 | over a sustained period | 5 |
|
| 18 | over a ten-year period | 5 |
|
