| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] over a long period [prep] | 45 |
|
| 2 | [noun] over a long period of | 40 |
|
| 3 | [noun sg] over a long period [prep] | 37 |
|
| 4 | [noun pl] over a long period [prep] | 7 |
|
