SN4 ""

No	Pattern	Freq
1	[noun] over a [adj] period	289
2	[noun sg] over a [adj] period	172
3	[noun pl] over a [adj] period	98
4	[verb] over a [adj] period	86
5	[vb pp] over a [adj] period	83
6	[adv] over a [adj] period	43
7	[adv] over a [adj] period	29
8	[adj] over a [adj] period	27
9	[conj] over a [adj] period	17
10	[adv prt] over a [adj] period	14
11	[adj] over a [adj] period	13
12	[coord] over a [adj] period	11
13	[n mass] over a [adj] period	10
14	[num] over a [adj] period	9
15	[noun prp] over a [adj] period	9
16	out over a [adj] period	6
17	that over a [adj] period	6
18	million over a [adj] period	6
19	out over a [adj] period	6
20	[that] over a [adj] period	6
21	[pron] over a [adj] period	6
22	million over a [adj] period	6
23	that over a [adj] period	6
24	or over a [adj] period	6
25	or over a [adj] period	6
26	time over a [adj] period	5
27	[no cls] over a [adj] period	5
28	money over a [adj] period	5
29	develop over a [adj] period	5
30	in over a [adj] period	5