| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | for [prep] [adv] a century | 6 |
|
| 2 | for [prep] [adv] a century | 6 |
|
| 3 | for [prep] [adv] a century | 6 |
|
| 4 | for [prep] least a century | 6 |
|
| 5 | for at [adv] a century | 6 |
|
| 6 | for at [adv] a century | 6 |
|
| 7 | for [prep] least a century | 6 |
|
