Using JS to find a year from serial numbers

Hello, I am just learning JavaScript and I am lost where to start on a project and I’d be grateful for any help. I have the following problem to solve.

I have a list of serial numbers, a from and to set of numbers that correlate to a year. I’d like to have a way to have a user enter a serial number, and have the year returned as the answer. For example;

100001 to 100100 = 1990

100101 to 100200 = 1991

100200 to 100300 = 1992

so if the user enters 100145 the answer 1991 would be returned…

Thank you for having taken the time to read this but without knowing how to look for the correct code / function it’s hared to find the answer - catch 22.