Monthly Rolling Spending Totals?

Is there an easy way to display as a graph a rolling view of spending totals over a fixed period? I'd like to see how my spending is over a 30 day period for a long period of time to see if there are any interesting trends. Right now I log in daily and can check this on the main banking page but I'd love to have easy access to historical data to make sure my budget is generally staying in balance for an extended period of time.

These are the closest I can think of.

1. Export a weekly chart of spending & income and plot in a spreadsheet. If it's going up, great!
2. Daily view of spending in Calendar. Easy to see trends but I can't export and it's not a rolling total.

Both give a bit of what I want but not everything. Any ideas?