Response rate data as of the final hours of the census shows a major disparity between Westchester's most affluent and most in-need communities.

People of color, immigrants, those in poverty and seniors are the most undercounted on the census, historically - and data from the Westchester County Complete Count Committee reflects that.

Port Chester at 56%, Mount Vernon at 57% and Yonkers at 61% have the lowest reporting rates in the county.

Scarsdale at 84%, as well as New Castle and Pelham Manor at 82% lead all municipalities.

Westchester Community Foundation executive director Laura Rossi says a lack of access to technology, fear of reporting and the constantly changing deadline to submit information are to blame. Westchester Community Foundation provided $150,000 in grants to help get people counted.

"We've known that 300,000 folks in Westchester County are hard to count. We've got data from that before the counting even started. That's a significant portion," she says.

A representative for the U.S. Census Bureau says census takers have followed up with nearly everyone in Westchester who didn't self-report their data for a total response rate of 99.9%.