| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] up over a period | 7 |
|
| 2 | built up over a period | 5 |
|
| 3 | [vb pp] up over a period | 5 |
|
| 4 | build up over a period | 5 |
|
| 5 | up over a period [prep] | 8 |
|
| 6 | up over a period of | 8 |
|
| 7 | up over a period [prep] | 8 |
|
| 8 | up over a period of | 8 |
|
