| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] [prep] several years | 144 |
|
| 2 | [verb] on [prep] years | 53 |
|
| 3 | [verb] on [prep] several | 22 |
|
| 4 | on [prep] several years | 5 |
|
