| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] have been operating for | 8 |
|
| 2 | [noun sg] have been operating for | 6 |
|
| 3 | have been operating for [adj] | 6 |
|
| 4 | have been operating for [adv] | 6 |
|
| 5 | have been operating for [adv] | 6 |
|
| 6 | have been operating for [num] | 5 |
|
