| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | date back [prep] the [num ord] [noun] | 7 |
|
| 2 | date back [prep] the [num ord] [noun sg] | 6 |
|
| 3 | date back [prep] the [num ord] century | 6 |
|
| 4 | date back [prep] the [num ord] century | 6 |
|
