Errors Reading a Lookup Table

Hi, I am building a GPT with GPT Builder to identify certain characteristics of a precision instrument based on its serial number and provide an assessment on whether it is all original or has been tampered with. One of the most basic characteristics to identify is the production year of the instrument. I fed my GPT a knowledge base which included a table that has 3 columns: Serial Start, Serial End, and Production Year. (see attached picture). Let’s say I want to identify the production year of a part with serial number 250. I want ChatGPT to lookup where 250 falls into between Serial Start and Serial End and tell me the corresponding Production Year in the same row. It does this correctly sometimes, but often makes mistakes. For example it can get the range correct, but select a different production year. How can I optimize my simple chart so that it does not make this mistake?