3% of $120k is $3,600
20 years of $3,600 is $72,000
This is beyond the range stated.
Having worked for years in IT for a municipal service, our standard formula was a raise of 0% to 3% based on a performance rating, with 0% being "you're on a PIP and going to be fired soon" and 3% being a top-performer.
This is speculation at this point - but I would assume NYC works against a similar system.
You’ll start on the low end and get a 2k bump per year for a decade or two, eventually hitting the cap.