| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [num] years [prep] | 3213 |
|
| 2 | [prep] [art] [num] [prep] | 2771 |
|
| 3 | [prep] [art] [num] years | 1318 |
|
| 4 | [art] [num] years [prep] | 591 |
|
| 5 | [prep] [art] years [prep] | 579 |
|
