| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun pl] over a long period | 34 |
|
| 2 | [noun pl] [prep] a long period | 29 |
|
| 3 | [noun pl] [prep] a longer period | 13 |
|
| 4 | [noun pl] for a long period | 6 |
|
