| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [prep] [num] year ['s] [noun] | 63 |
|
| 2 | [be] [prep] [num] [noun] ['s] duration | 56 |
|
| 3 | [be] [prep] [adj] year ['s] duration | 51 |
|
| 4 | [be] [prep] [num] year ['s] duration | 51 |
|
| 5 | [be] [prep] [num] year [unc] duration | 51 |
|
