Query: Administrative costs in US health care

[Gar Lipow]

The usual figures for Admin costs+insurance profits+hefty CEO salaries 
in U.S. health care given by single payer groups are 25%. But US
department of health and human services gives figures of around 5% (not
counting profits and CEO salaries, but still...)

Anyone have some insight into how these different figures are calculated
-- and some reliable sources to give in debates for the 25% figures...?