| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [adv] [num] years i | 10 |
|
| 2 | for [adv] [num] years i | 8 |
|
| 3 | for [adv] [num] years i | 8 |
|
| 4 | [prep] over [num] years i | 7 |
|
