Percentage Increase/Decrease Calculation

[clos2818]

Team 

I need to figure out how to calculate the increase/decrease in percentage. for example

1. Original Number - 1000 

2. New Numer - 500

I want to show the percentage it decreases from. These numbers will change from home to home. 

Thank you 

[Michael_Wills · Accepted solution]

Where are these numbers (original and new) coming from / stored? Also, what is 'home to home'?