| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adj] period of | 143 |
|
| 2 | over a [adj] period of | 137 |
|
| 3 | over a [adj] period of | 134 |
|
| 4 | over a long period of | 84 |
|
| 5 | over a long period of | 77 |
|
| 6 | over a [adj -er] period of | 9 |
|
| 7 | over a short period of | 8 |
|
| 8 | over a prolonged period of | 8 |
|
| 9 | over a prolonged period of | 8 |
|
| 10 | over a considerable period of | 7 |
|
| 11 | over a longer period of | 7 |
|
| 12 | over a short period of | 7 |
|
| 13 | over a considerable period of | 7 |
|
| 14 | over an [adj] period of | 6 |
|
| 15 | over a given period of | 5 |
|
| 16 | over a given period of | 5 |
|
