For the fifth consecutive year, Pinellas County has declined in population.
While Pinellas shrinks, other Tampa Bay counties — particularly Pasco — continue to grow, according to figures released Thursday by the Census Bureau.
The population figures, which cover from July 2007 to July 2008, show that Pinellas County lost 4,184 people in that time, bringing its population to 910,260.
Hillsborough, which gained 10,266 residents, has a population of 1,180,784. It was the county's eighth straight year of growth.
Hillsborough ranks as the 32nd-largest county in the country. Pinellas is 47th.
Pasco County, which grew by almost 10,000 people last year, was listed as the 59th-fastest-growing county in the nation since 2000. With 471,028 residents, it showed a 36.6 percent population increase over that period.
And Hernando County was 96th-fastest growing in that time, up 31.3 percent to 171,689 since the last census in 2000.
Some in Pinellas reacted skeptically to the news of the population drop.
"It's called PFA: plucked from air," Nikki Ubaldini, a broker with Keller Williams Realty in Palm Harbor, said of the report. "I'm serious. We're not seeing that trend at all."
First-time home buyers and relocating families continue to move into Pinellas, which has the region's lowest foreclosure rate, Ubaldini said.
"It's not like in Hillsborough County, with row after row of empty houses," said Realtor Nancy Riley with Coldwell Banker Residential Real Estate.
Riley speculated that some of the departures could be attributed to renters who no longer want to stick it out in Florida's troubled economy or snowbirds who no longer declare Florida their home state.
Pinellas County remains the state's most densely populated county, with about 3,250 people per square mile. The county is about 97 percent built out.
Population estimates are based on several factors, including births, deaths and migration. Historically, more people die in Pinellas than are born, said county Planning Department director Brian Smith, meaning that the county depends on people moving in to keep population levels steady.
Smith said he suspects that housing costs kept people from moving to Pinellas when the real estate market was booming three years ago.
Now that the economy is in tatters, he said, fewer people are willing to bear the risks and costs of relocation.
Pinellas County's population was 921,482 during the last official census in 2000. (The next begins in April 2010). It grew slightly each year and crested at 923,543 in 2002.
The county lost just a few hundred residents a year until the 2006 report, then dropped by almost 4,000 to 920,533 in 2006. The exodus began from there, with the county shedding 10,273 people over the next two years.
During this latest studied period, Pinellas County had 910,260 residents, down from 914,444 the previous year. That works out to only a 0.5 percent decrease.
Smith cautioned that the federal government's latest numbers are just guesses (although they are based on things such as birth certificates, death records and tax returns), and he and his staff are eager to see the results of the next official census.
"In the long term, we may have more natural growth as the county gets younger," Smith said.
Times staff writers Jim Thorner, Donna Winchester, Brant James and Will Van Sant contributed to this report. Kameel Stanley can be reached at (727) 893-8643 or firstname.lastname@example.org.