This is the 459th most frequent Croatian word.
godišnje
"Annually" or "per year."
The word 'godišnja' here is an adjective meaning 'annual', describing the noun 'plaća' (salary).
Prosječna godišnja plaća u Hrvatskoj raste iz godine u godinu.
The average annual salary in Croatia increases year by year.
The word 'godišnje' functions as an adverb meaning 'per year', modifying the verb 'imamo' (we have).
U zoološkom vrtu imamo 5000 posjetitelja godišnje.
We have 5000 visitors per year in the zoo.
In this sentence, 'godišnje' again acts as an adverb, denoting the frequency of the event happening 'once a year', modifying 'se održava' (takes place).