SN4 ""

No	Pattern	Freq
1	[art] period [prep] [adj] years	262
2	[art] period [prep] [adj] years	262
3	[art] period of [adj] years	259
4	[art] period of [adj] years	259
5	a period [prep] [adj] years	244
6	a period [prep] [adj] years	244
7	[art] period [prep] [num] years	243
8	[art] period [prep] five years	36
9	[art] period [prep] five years	36
10	[art] period [prep] two years	35
11	[art] period [prep] two years	35
12	[art] period [prep] three years	34
13	[art] period [prep] three years	34
14	the period [prep] [adj] years	18
15	the period [prep] [adj] years	18
16	[art] period [prep] [det] years	18
17	[art] period [prep] ten years	13
18	[art] period [prep] ten years	13
19	[art] period [prep] twenty years	11
20	[art] period [prep] twenty years	11
21	[art] period [prep] six years	10
22	[art] period [prep] six years	10
23	[art] period [prep] four years	10
24	[art] period [prep] four years	10
25	[art] period [prep] several years	9
26	[art] period [prep] several years	9
27	[art] period [prep] seven years	8
28	[art] period [prep] seven years	8
29	[art] period [prep] 10 years	7
30	[art] period [prep] 10 years	7