| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | at [adv] 20 years | 13 |
|
| 2 | at [adv] 20 years | 13 |
|
| 3 | at least 20 years | 11 |
|
| 4 | at least 20 years | 11 |
|
