Why don't you go get the information? Maybe you could get a more recent expenditure report.
http://www.bls.gov/
Can you get some html thangs happening and put up a graph of income vs effective rates that will overlay income tax rates by income AND nrst rate by spending?
The BLS acknowledges the rather large difference between reported income and expenditures. It relies on self reporting when gathering information and admits a significant margin of error.