Best design pattern for a Electric Bills System in Java Spring

as a "learning project" I'm trying to implement a Electric bill System, actually I use a XLS spreadsheet. I have 52 APARTAMENTS and monthly I receive the MEASURE from the residential electric meters. The difference between the 2th month and the 1st if the electric CONSUMPTION.

So should be as simple as a class for APARTAMENTS that "has a" MEASURE and another for CONSUMPTION ? or there is some design patter to apply?

I want to implement the system in Spring boot.