From the Document: "This report provides a graphical overview of historical trends in discretionary budget authority (BA) from FY1977 through FY2016, preliminary estimates for FY2016 spending, and the levels reflecting the President's proposals for FY2016 through FY2021 using data from the FY2017 budget submission released on February 9, 2016. This report, by illustrating trends in broad budgetary categories, provides a starting point for discussions about fiscal priorities. Other CRS products analyze spending trends in specific functional areas. Functional categories (e.g., national defense, agriculture, etc.) provide a means to compare federal funding for activities within broad policy areas that often cut across several federal agencies. Subfunction categories provide a finer division of funding levels within narrower policy areas. Budget function categories are used within the budget resolution and for other purposes, such as estimates of tax expenditures."
CRS Report for Congress, R41726
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html