Source: http://www.cbo.gov/ftpdocs/88xx/doc8885/EffectiveTaxRates.shtml Historical Effective Federal Tax Rates: 1979 to 2005 Congressional Budget Office
Source: http://www.cbo.gov/ftpdocs/88xx/doc8885/EffectiveTaxRates.shtml Historical Effective Federal Tax Rates: 1979 to 2005 Congressional Budget Office
Progressiveness of Income Taxes by Country
