Provides annual income, financial, and tax data, based on individual and corporate tax returns and returns filed by tax-exempt organizations. SOI also provides periodic data based on other returns, such as those filed by estates, for estimating wealth of the living top wealth holders, as well as on various other tax and information returns and schedules, for producing such estimates as U.S. investments abroad, foreign investments in the United States, and gains or losses from sales of capital assets.