The response is worst in the Bronx, where only about 2 percent of residents sent their census forms back.
Even in Manhattan, city officials estimate only 7 percent of residents have returned the forms.
Ten days after 120 million Census questionnaires were mailed to every address in the country, some 16 percent have been returned.
The Census Bureau posts daily "participation rates" on its 2010census.gov Web site for every state, county, city, town, township, Indian reservation and neighborhood. It partnered with Google to provide the interactive maps, which will be updated every Monday through Friday.