| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun pl] there have been a [adj] | 45 |
|
| 2 | years there have [been] a [adj] | 36 |
|
| 3 | [noun pl] there has [been] a [adj] | 35 |
|
| 4 | [noun pl] there had [been] a [adj] | 8 |
|
