| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over [art] long period | 235 |
|
| 2 | over a long period | 232 |
|
| 3 | over a long period | 232 |
|
| 4 | over [art] long period | 183 |
|
| 5 | over [art] longer period | 52 |
|
