Public debate over taxes has typically focused on the federal income tax, but that now accounts for less than a third of the total tax revenues collected by federal, state and local governments. To analyze the total burden, The Times created a model, in consultation with experts, which estimated total tax bills for each taxpayer in each year from 1980, when the election of President Ronald Reagan opened an era of tax cutting, up to 2010, the most recent year for which relevant data is available.