year in year out

[vil]

Dear teachers,

Would you be kind enough to give me your considered opinion concerning the interpretation of the expression in bold in the following sentence?

To go chained body to body into the wet earth, year in year out, until they died of the damp ague – rather would they be burned alive. (John Steinbeck, “Cup of Gold”)

year in year out = year by/after year

V.

[Tdol]

Year after year sounds better to me as it gives a stronger idea of the duration.