Using the Historical Tables available at the budget tab of the website of the U.

Hi I need help trying to understand what formula that is being used. Using the Historical Tables available at the budget tab of the website of the U.S. Office of Management and Budget, prepare a analysis of the trends in the following data: total federal outlays, total defense spending, and total mandatory spending. Do the analysis in both current and constant dollars. Provide your interpretation of what forces are driving the patterns that you observe. I found an example on this site but no explanation on what to use.