This is the 14927th most frequent Polish word.
rocznej
"Rocznej" means "annual" or "yearly" in English.
The word 'rocznej' is used here as an adjective modifying 'nauki' (study), denoting something that lasts one year.
Mam plan rocznej nauki języka.
I have a plan for a year-long language study.
Here, 'rocznej' modifies 'działalności' (activity), indicating that the activity takes place or is analyzed annually.
Podsumowanie rocznej działalności firmy pokazuje wzrost.
The summary of the annual activity of the company shows growth.
In this sentence, 'rocznej' describes 'pracy' (work), referring to work done over the span of a year.