| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | two years ' [noun] | 173 |
|
| 2 | [adj] years ' duration | 71 |
|
| 3 | two [noun pl] ' duration | 9 |
|
| 4 | two [noun] ' duration | 9 |
|
| 5 | two years [unc] duration | 7 |
|
| 6 | two year ' duration | 7 |
|
