| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | been [vb pp] in [adj] years | 88 |
|
| 2 | been [vb pp] [prep] recent years | 87 |
|
| 3 | been made [prep] [adj] years | 9 |
|
| 4 | been developed [prep] [adj] years | 6 |
|
| 5 | been [vb pp] over [adj] years | 6 |
|
| 6 | been [vb pp] [prep] previous years | 6 |
|
| 7 | been used [prep] [adj] years | 5 |
|
| 8 | been eroded [prep] [adj] years | 5 |
|
