How to calculate percentage when old value is ZERO

Question

I need the logic for the following situation. I am clueless in doing this.

Consider for January I have 10$ revenue and f

Answer 1

This is most definitely a programming problem. The problem is that it cannot be programmed, per se. When P is actually zero then the concept of percentage change has no meaning. Zero to anything cannot be expressed as a rate as it is outside the definition boundary of rate. Going from 'not being' into 'being' is not a change of being, it is instead creation of being.