| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] over a period of | 60 |
|
| 2 | [adv] over a period [prep] | 60 |
|
| 3 | [adv] over a period of | 60 |
|
| 4 | [adv] over a period [prep] | 34 |
|
| 5 | [adv prt] over a period [prep] | 25 |
|
| 6 | up over a period [prep] | 8 |
|
| 7 | up over a period [prep] | 8 |
|
| 8 | gradually over a period [prep] | 7 |
|
| 9 | gradually over a period [prep] | 7 |
|
| 10 | out over a period [prep] | 5 |
|
| 11 | out over a period [prep] | 5 |
|
