adverb
Indicates that something happens or is done once each year, on a yearly basis.
この町では一年ごとに祭りが開かれる。
In this town, a festival is held every year.
契約は一年ごとに更新される。
The contract is renewed annually.
Compound of 一年 (one year) and the suffix ごと (every). The suffix ごと attaches to nouns indicating time or units to express 'every ~'.