Pretty much all the Census Bureau stuff I saw concentrated on population quintiles and the top 5%. That's what's hard about this stuff unless you are a full-time specialist in economic statistics---it's hard to find numbers that match up exactly.
One other problem with a lot of these calculations (shooting down my own table, now): some of the figures are in terms of household income, and other figures are dealing with individuals. I would think the trends would move in the same direction for these but it's a complicating factor.