| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv prt] [prep] a [adj] period [prep] | 16 |
|
| 2 | [adv prt] [prep] a [adj] period [prep] | 14 |
|
| 3 | [adv prt] [prep] a [adj] period of | 10 |
|
| 4 | [adv prt] [prep] a [adj] period of | 10 |
|
| 5 | [adv prt] over a [adj] period [prep] | 6 |
|
