year by year
/ˈjɪə bʌɪ ˈjɪə/ /ˈjəː bʌɪ ˈjəː/adverb
In each successive year, every year; annually; (also in early use) †continuously for a number of years (obsolete ).
adjective
Relating to, or giving details of, each successive year; that occurs in each successive year.
Origin
Late Middle English; earliest use found in John Gower (d. 1408), poet. From year + by + year.