ごとに

ごとに
suffix
every ~; each ~; at intervals of ~
grammatical
1. every ~; each ~; at intervals of ~
Attaches directly to a noun, a counter phrase, or the dictionary form of a verb, and marks something that happens with each member of a set or at each repetition: (えき)ごとに (at every station), ()うごとに (every time we meet). Also written (ごと)に.
I take the medicine every three hours.
()ごとに(かれ)元気(げんき)になっていく。
Every time I see him he seems healthier.
Passengers got off at each station, and the train gradually grew quiet.

Distributive: it picks out every member of a set, one after another, without skipping any.

Common patterns

COMMON MISTAKE — ごとに vs おき:
おき means "skipping one in between," so the two are easy to confuse: