| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] [prep] [adv] a year | 136 |
|
| 2 | [noun] [prep] at [adv] a | 132 |
|
| 3 | [prep] at [adv] a year | 39 |
|
| 4 | [noun] at [adv] a year | 5 |
|
