How old is Nova in Alita?

Excuse me, I was wondering if you could clarify something for me about the character Nova in the film "Alita: Battle Angel." Specifically, I'm curious about how old Nova is supposed to be in the movie. I understand that he's a pivotal character and has a significant impact on the story, but I haven't been able to find a definitive answer about his age. Could you provide any insight or clarification on this matter? Thank you in advance for your assistance.