| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [num] year [noun] | 282 |
|
| 2 | [n mass] [prep] a [num] [noun] | 108 |
|
| 3 | [n mass] [prep] [num] year [noun] | 14 |
|
| 4 | [n mass] [prep] a [num] year | 7 |
|
