| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a [noun sg] [prep] [adj] years it | 8 |
|
| 2 | a [noun] of [adj] years it | 8 |
|
| 3 | a [noun] [prep] [num] years it | 8 |
|
| 4 | a period [prep] [adj] years it | 5 |
|
| 5 | a period [prep] [adj] years it | 5 |
|
