| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a period of [adj] years | 109 |
|
| 2 | [prep] a period of two years | 32 |
|
| 3 | [prep] a period of two years | 32 |
|
| 4 | over a period of two [noun] | 25 |
|
| 5 | over a period of two [noun pl] | 25 |
|
| 6 | over a [noun] of two years | 13 |
|
| 7 | over a [noun sg] of two years | 13 |
|
| 8 | over [art] period of two years | 12 |
|
| 9 | over [art] period of two years | 12 |
|
| 10 | over a period of two years | 12 |
|
| 11 | over a period of two years | 12 |
|
| 12 | over a period of two year | 12 |
|
| 13 | over a period of two years | 12 |
|
| 14 | over a period [prep] two years | 12 |
|
| 15 | over a period [prep] two years | 12 |
|
| 16 | over a period of two years | 12 |
|
