| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [adv] three years | 197 |
|
| 2 | [prep] three years [unc] | 102 |
|
| 3 | [adv] three years [unc] | 14 |
|
| 4 | [prep] [adv] three [unc] | 5 |
|
