You can change years by using the left/right keyboard arrows, clicking the "year" buttons toward the upper left and right of the screen, or (if your device has a large enough screen) by clicking on the "mini" graph over time that is at the bottom of the page.

With the exception of the deficit and "net interest" rectangles, you can drill down to line items for any year by clicking on the one of the rectangles, which will then show a table, sortable by amount, SubFunction, Agency, or Bureau.

For each row of a detail table, you can click on the icon to display an interactive graph over time for that line item.

To get you started, you can take a tour that will highlight a few interesting things, as well as show some of the features of the visualization. You can exit or resume the tour at any time.