| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] years [subord] [pron] | 57 |
|
| 2 | [prep] several years [pron] | 31 |
|
| 3 | several years [subord] [pron] | 20 |
|
| 4 | [prep] several years [subord] | 18 |
|
