SN4 ""

No	Pattern	Freq
1	[prep] [noun] over a [adj] period	58
2	[prep] [noun] over a [adj] period	58
3	[prep] [noun] over a [adj] period	58
4	[prep] [noun] over a [adj] period	51
5	of [noun] over a [adj] period	35
6	of [noun] over a [adj] period	35
7	[prep] [noun sg] over a [adj] period	31
8	[prep] [noun] over a long period	31
9	[prep] [noun] over a long period	25
10	[prep] [noun pl] over a [adj] period	17
11	in [noun] over a [adj] period	8
12	in [noun] over a [adj] period	8
13	[prep] [noun] over a [adj -er] period	7
14	[prep] [noun prp] over a [adj] period	6
15	[prep] [noun] over a longer period	6
16	to [noun] over a [adj] period	5
17	to [noun] over a [adj] period	5