| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun prp] [prep] [adj] months | 209 |
|
| 2 | [noun] [prep] 18 months | 165 |
|
| 3 | [noun prp] [prep] 18 [noun] | 107 |
|
| 4 | [noun prp] [prep] 18 [noun pl] | 27 |
|
| 5 | [noun prp] [prep] 18 month | 13 |
|
