| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adj] [noun] over a prolonged period | 6 |
|
| 2 | [adj] [noun] over a prolonged period | 6 |
|
| 3 | [noun] over a prolonged period [prep] | 8 |
|
| 4 | [noun] over a prolonged period [prep] | 8 |
|
| 5 | [noun] over a prolonged period of | 7 |
|
| 6 | [noun] over a prolonged period of | 7 |
|
