year over year
/ˈjɪər əʊvə ˈjɪə/ /ˈjəːr əʊvə ˈjəː/adverb
1Repeatedly over a number of years; for years without change. Compare year on year. Now rare.
2With reference to trends, gradual increases or decreases, etc.: with or in each passing or successive year.
3With reference to figures, financial data, etc.: as compared with the corresponding information from the previous year.
adjective
Economics and Finance (chiefly North American ). Relating to or shown by a comparison of corresponding figures from two consecutive years.
Origin
Early 19th century; earliest use found in Arthur Aikin (1773–1854), natural scientist and author. From year + over + year.