SN4 ""

No	Pattern	Freq
1	have been [verb] for [det] years	106
2	have been [vb pp] [prep] [det] years	82
3	have been [verb] [prep] many years	75
4	has been [verb] [prep] [det] years	44
5	had been [verb] [prep] [det] years	37
6	have been [v-ing] [prep] [det] years	36
7	have been [verb] [prep] [det] years	28
8	have been [verb] [prep] some years	24
9	have been [verb] [prep] several years	19
10	have been know [prep] [det] years	15
11	have been known [prep] [det] years	15
12	have been use [prep] [det] years	12
13	have been used [prep] [det] years	12
14	have been [verb] over [det] years	11
15	have been establish [prep] [det] years	5
16	've been [verb] [prep] [det] years	5
17	have been established [prep] [det] years	5