| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | twenty years of [noun] | 42 |
|
| 2 | [adv] years of [noun] | 10 |
|
| 3 | [adv] twenty years of | 8 |
|
| 4 | [adv] twenty years [noun] | 6 |
|
