Run the same nodes on multiple files

I have a workflow that uses 2 excel readers, one for January and the other for February, and they have nodes that count the number of students in my class for each month, and then I have joiners and such to see the % of change in student attendance from Jan to Feb. How can I run these nodes for every months excel sheet January - December, see the % of change every month, without having 12 different excel readers and sets of the same few nodes? I know to use List files/folders and loop node, I’m just not sure where and how I’d use it here to do what I need, especially since I need data from 2 months to get one row of “% of change” data. Any example workflows are appreciated