No | Pattern | Freq | Relations |
---|---|---|---|
1 | and [prep] a period of | 23 | |
2 | and [prep] a period of | 23 | |
3 | and over a period of | 12 | |
4 | and over a period of | 12 | |
5 | and for a period of | 6 | |
6 | and for a period of | 6 | |
7 | and after a period of | 5 | |
8 | and after a period of | 5 |