When you make a table in data.census.gov you can click on "More Tools" in the upper right corner and then select Cite
Basic Format for APA 6th edition
U.S. Census Bureau (year data was published). Name of data or report. Retrieved from [URL].
Chicago Style 16th ed.
United States Census Bureau. Name of Table. Data.Census.Gov <URL> (The date the Table was generated)
See the Publication Manual of the American Psychological Association. This book is available at multiple locations in the library system.
See page 53 of the MLA Handbook, 8th Edition. This book is available at multiple locations in the library system.