Source: U.S. Department of the Treasury. Internal Revenue Service  

Release: SOI Tax Stats - Historical Data Tables  

Units:  Number of Returns, Not Seasonally Adjusted

Frequency:  Annual

Includes credits such as the low-income housing credit, child adoption credit, and "empowerment zone employment" (EZE) credit (not shown separately). Includes the portion of refundable credits used to offset income tax before credits.

For additional information about the return filing requirements, see the annual reports, Statistics of Income-Individual Income Tax Returns at https://www.irs.gov/uac/soi-tax-stats-historical-data-tables.