| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] over a period [prep] [noun] | 39 |
|
| 2 | [adv] over a period [prep] [noun pl] | 17 |
|
| 3 | [adv] over a [noun sg] [prep] years | 16 |
|
| 4 | [adv] over a [noun] [prep] years | 16 |
|
| 5 | [adv] [prep] a period [prep] years | 7 |
|
| 6 | [adv] over a period [prep] years | 7 |
|
| 7 | [adv] [prep] a period [prep] years | 7 |
|
| 8 | [adv] over [art] period [prep] years | 7 |
|
| 9 | [adv] over [art] period [prep] years | 7 |
|
| 10 | [adv] over a period [prep] years | 7 |
|
| 11 | [adv] over a period [prep] year | 7 |
|
| 12 | [adv] over a period [prep] years | 7 |
|
