May I ask how do you calculate the ROI in excel if 0= owe and 1= profit. I have upload the excel attachment for your reference. Do view on the ROI section whereby 0 and 1 are still struggling.
What is the total amount of investment you have made? I guess the numerator will be the return that is your Net cash flow, it wud be a simple division formula, ROI=Net Return on investment/ otal investment, I do not think this is an excel question, this will be more or less a ratio analysis question.