SN4 ""

No	Pattern	Freq
1	[noun] over the [adj] 20 years	64
2	[noun sg] over the [adj] 20 years	30
3	[noun pl] over the [adj] 20 years	25
4	[verb] over the [adj] 20 years	14
5	[vb pp] over the [adj] 20 years	11
6	[noun prp] over the [adj] 20 years	8
7	[adj] over the [adj] 20 years	7
8	cent over the [adj] 20 years	6
9	cent over the [adj] 20 years	6
10	[no cls] over the [adj] 20 years	6
11	[adv] over the [adj] 20 years	6
12	[unc] over the [adj] 20 years	6
13	[pron] over the [adj] 20 years	5
14	[adv] over the [adj] 20 years	5
15	over the [adj] 20 years [verb]	12
16	over the [adj] 20 years [conj]	10
17	over the [adj] 20 years [art]	10
18	over the [adj] 20 years [art]	10
19	over the [adj] 20 years [prep]	10
20	over the [adj] 20 years [prep]	10
21	over the [adj] 20 years [coord]	8
22	over the [adj] 20 years the	7
23	over the [adj] 20 years the	7
24	over the [adj] 20 years have	7
25	over the [adj] 20 years [vb -s]	6
26	over the [adj] 20 years or	5
27	over the [adj] 20 years or	5
28	over the [adj] 20 years has	5