| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [prep] [adj] years ' duration | 49 |
|
| 2 | [is] [prep] [adj] years ' [noun] | 46 |
|
| 3 | [is] [prep] [adj] [noun] ' duration | 45 |
|
| 4 | [is] [prep] [adj] years [unc] duration | 45 |
|
| 5 | [is] [prep] [adj] years ' duration | 45 |
|
| 6 | [is] [prep] [adj] year ' duration | 45 |
|
| 7 | [is] [prep] [adj] [noun pl] ' duration | 45 |
|
