<page_title> Washington County, Iowa </page_title> <section_title> Demographics </section_title> <table> <cell> 2000 <col_header> Historical population </col_header> <col_header> Census </col_header> </cell> <cell> 20,670 <col_header> Historical population </col_header> <col_header> Pop. </col_header> </cell> </table>
As of the census of 2000, there were 20,670 people residing in Washington County, Iowa.