| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] 18 months ' [noun] | 18 |
|
| 2 | [prep] 18 months ' [noun sg] | 18 |
|
| 3 | [prep] 18 months ' [noun] | 18 |
|
| 4 | [prep] 18 months ' imprisonment | 11 |
|
| 5 | [prep] 18 months ' imprisonment | 11 |
|
| 6 | to 18 months ' [noun] | 11 |
|
