| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adj] twenty years [prep] [pos pn] [noun] | 9 |
|
| 2 | [num ord] twenty years [prep] [pos pn] [noun] | 7 |
|
| 3 | last twenty years [prep] [pos pn] [noun] | 6 |
|
| 4 | last twenty years [prep] [pos pn] [noun] | 6 |
|
