SN4 ""

No	Pattern	Freq
1	[noun] over a [noun] period	9
2	[noun sg] over a [noun] period	5
3	over a [adj] [noun] period	142
4	over a [num] [noun] period	132
5	over a three [noun] period	21
6	over a three [noun] period	21
7	over a five [noun] period	17
8	over a five [noun] period	17
9	over a two [noun] period	17
10	over a two [noun] period	17
11	over a six [noun] period	11
12	over a six [noun] period	11
13	over a one [noun] period	8
14	over a four [noun] period	8
15	over a one [noun] period	8
16	over a four [noun] period	8
17	over a [adj] [noun] period	7
18	over a 10 [noun] period	6
19	over a 10 [noun] period	6
20	over a ten [noun] period	5
21	over a ten [noun] period	5
22	over a [noun] period [prep]	6
23	over a [noun] period [prep]	6
24	over a [noun] period of	5
25	over a [noun] period of	5