| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | for 30 year | 140 |
|
| 2 | [v-ing] for year | 112 |
|
| 3 | [v-ing] for 30 | 14 |
|
| 4 | [v-ing] 30 year | 10 |
|
