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

You can add 1 to each example New = 5; old = 0;

(1+new) - (old+1) / (old +1) 5/ 1 * 100 ==> 500%