| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] four years | 820 |
|
| 2 | [adv prt] [prep] four | 662 |
|
| 3 | [adv prt] [prep] years | 149 |
|
| 4 | [adv prt] four years | 10 |
|
