Your Proformas are a prediction for how things will turn out given your decisions and the spreadsheets' limited knowledge of the situation. Last Year's Reports are the results of the actual competition, when your plan was put into play against your competitors' plans.
The Proformas are designed to help you make decisions. They do not go into nearly as much detail as The Capstone® Courier or your Annual Report. Many items in the Proformas represent generalizations, and other factors, like write-offs, are ignored. Instead, the Proformas offer a simplified picture of potential outcomes. To use them effectively, think of them as a scenario tool.