| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | twenty years ' [noun sg] | 37 |
|
| 2 | [prep] twenty years ' | 21 |
|
| 3 | [prep] years ' [noun sg] | 20 |
|
| 4 | [prep] twenty years [noun sg] | 9 |
|
