| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | for 20 years | 221 |
|
| 2 | in 20 years | 65 |
|
| 3 | to 20 years | 64 |
|
| 4 | after 20 years | 52 |
|
| 5 | of 20 years | 46 |
|
| 6 | within 20 years | 14 |
|
| 7 | at 20 years | 9 |
|
| 8 | with 20 years | 9 |
|
