In my data sample I have 15 customers and 10 products ( in real life a lot more and it keeps changing all the time). What I am trying to achieve in Column B is to have a formula which repeats the same customer number for the number of rows there are products (15) and then increase the customer by 1 and repeat again for the same number of rows. Repeat the same process until customer number is 15 and then restart everything again from customer number 1. Effectively repeat the same process 12 times which represents 12 months.
So far, I have managed to come up with the below formula, but not sure how to improve it so that it restarts after customer number 15 is reached instead of keep increasing by 1.
Colum G in the attached is the way I would want the formula to work, so any help is much appreciated