This is the 160th most frequent Polish word.
zostało
"Zostało" means "remained" or "was left" in English.
In this sentence, 'zostało' is used to indicate that a certain amount of money remains.
W skarbonce zostało pięć złotych.
There are five zlotys left in the piggy bank.
Here, 'zostało' is used to describe something that persisted or stayed in people's memory.
Kiedy wybuchła wojna, zostało to w pamięci wielu ludzi.
When the war broke out, it remained in the memory of many people.
In this usage, 'zostało' expresses the scarcity of time remaining.