LAWRENCEVILLE -- Gwinnett's population increased by more than one third in the past decade, according to the recently released 2010 Census, which placed the county population at 805,321.
But with a quick look at the numbers, it would seem like Gwinnett, for the first time in decades, lost residents between 2009 and 2010.
Not so, said Mike Alexander of the Atlanta Regional Commission.
Even though the 2009 Census estimate had the county with 808,167 residents, the 2010 count is not a loss but instead just a more accurate number.
"The 2010 Census is a physical count," Alexander said. "When they do estimates, it's a completely different methodology. ... It's a very reasoned guess. It's not expected to be as accurate as the actual Census."
Alexander said the year-by-year estimates are hard, especially since information often lags by two years. With the county's growth surge at the beginning of the decade, it was hard to put statistics to the drastic slow down during the economic recession, he added.
"You don't really know how many people are moving into an area for the same year," he said. "They do a pretty good job, but with a diverse county like Gwinnett, it's hard."
Alexander said the 2009 number would likely be corrected by statisticians.
According to an ARC analysis, Gwinnett had the biggest population jump in metropolitan Atlanta. The closest second was Fulton County, which, with 104,575 new residents, had half of the population growth.