| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] four years | 820 |
|
| 2 | [prep] years [pers pn] | 217 |
|
| 3 | four years [pers pn] | 61 |
|
| 4 | [prep] four [pers pn] | 38 |
|
