The Internal Revenue Service is opening the proverbial Al Capone vault on its income tax statistics, stretching back nearly a century.

The online archive includes PDF files of historical statistical publications, including stats chronicling the first years of the modern federal individual income tax, which was enacted way back in 1913.

The 1916 report provides a time capsule of World War I era America, when the Honorable W.G. McAdoo was Secretary of the Treasury. That year, 437,036 tax returns were filed, showing an aggregate net income of less than $6.3 billion. Taxes that year averaged $396.73 and the average tax rate was 2.75 percent of the aggregate net income. Ah, if only.

The IRS archive presents digitized information on individuals, businesses, tax-exempt organizations, trusts and estates, and other taxed entities. The IRS said the information is intended to allow users to see how the tax system has evolved and changed over its nearly 100-year history and to examine historical trends.

The archive is available on the IRS Statistics of Income Division’s pages of,

Take the time machine there to the tax days of yore.