| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] the last 30 years | 71 |
|
| 2 | over the [num ord] 30 years | 44 |
|
| 3 | [prep] the next 30 years | 24 |
|
| 4 | in the [num ord] 30 years | 18 |
|
| 5 | for the [num ord] 30 years | 16 |
|
| 6 | during the [num ord] 30 years | 11 |
|
| 7 | of the [num ord] 30 years | 6 |
|
