| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a period of [adj] | 486 |
|
| 2 | a period [prep] rapid | 26 |
|
| 3 | a period [prep] considerable | 18 |
|
| 4 | a period [prep] great | 17 |
|
| 5 | a period [prep] intense | 15 |
|
| 6 | a period [prep] high | 13 |
|
| 7 | a period [prep] economic | 13 |
|
| 8 | a period [prep] relative | 13 |
|
| 9 | a period [prep] sustained | 12 |
|
| 10 | a period [prep] increasing | 9 |
|
| 11 | a period [prep] unprecedented | 8 |
|
| 12 | a period [prep] prolonged | 8 |
|
| 13 | a period [prep] severe | 8 |
|
| 14 | a period [prep] intensive | 6 |
|
| 15 | a period [prep] deep | 5 |
|
| 16 | a period [prep] military | 5 |
|
| 17 | a period [prep] stable | 5 |
|
| 18 | a period [prep] full | 5 |
|
| 19 | a period [prep] continental | 5 |
|
| 20 | a period [prep] political | 5 |
|
| 21 | a period in [adj] | 5 |
|
