Higher mail-in participation rates mean savings for taxpayers because there is no need to send a census taker to collect missing information from a household.
The national participation rate so far is 50 percent since the form was first sent out in the middle of March. Georgia lags behind at 47 percent participation, while South Carolina is outpacing the national average at 54 percent.
The South Carolina rate is notable because during the 2000 count the state had the second-worst mail-in participation rate at just 65 percent.
Nationally, the 2000 participation rate was 72 percent.
Aiken and Columbia counties are besting the national participation rate. Richmond County is slightly behind.
"We're all trying to motivate people to return those forms," said Ed Davis, the regional partnership coordinator for the Census Bureau. "That's the big message right now."
The cost of returning a census form by mail is little more than the cost of a postage stamp, but each time a census worker is dispatched to a household, that adds $57 to the taxpayer bill.
"You can see easily that it makes a lot of sense to simply mail the form back in," Davis said.
The once-a-decade count determines congressional representation and helps determine how $4 trillion in federal funds will be distributed during the next 10 years for projects such as roads, hospitals and education.
A census worker might be dispatched to a household even after a form has been returned depending on the date it is mailed because of the way the bureau keeps records, Davis said.
If that is the case, the house can turn away the census worker by telling them they have already mailed in the form, he said. That information will then be checked again against the census database.
The census is required by the U.S. Constitution and collects population data such as age, race and gender.