The possibility that the population of Washoe County declined last year doesn’t rattle business observers who watch population trends closely.

They say the estimated decline of 935 people — 0.2 percent of the Washoe County population — is simply too small to make much difference.

State Demographer Jeff Hardcastle said falling numbers of jobs in Washoe County played an important element in his estimate. He said Washoe County lost about 4,200 jobs, and government jobs accounted for about 2,000 of the total.

Historically, the demographer has said, 1.59 people have lived in Nevada for every job in the state’s economy. But that relationship has been less predictable since the onset of the recession when the number of jobs appears to have fallen faster than the population.

Hardcastle estimated that the Washoe County’s population stood at 421,593 on July 1, 2011. He estimated the population of Reno at 222,801 and the population of Sparks at 92,302.

During the economic boom years of 2004, 2005 and 2006, annual population growth topped 3 percent in Washoe County, and the growth rate in Sparks was nearly 5 percent in 2004-2005.

The demographer’s belief that the area’s population declined wasn’t immediately apparent in the housing market.

Demand from homebuyers, for instance, remained strong, said Kevin Sigstad, president of the Reno/Sparks Association of Realtors and the broker with Re/Max Premier Properties.

“Despite Washoe County’s recent population decline in 2011, the housing market has surprisingly continued to see increases in its existing home sales,” said Sigstad.

He noted that the number of sales of existing “stick-built” homes in the county during 2011 was 10 percent higher than a year earlier.

And apartment vacancies aren’t rising, either. Vacancies in major apartment complexes with 80 units or more stood at 6.56 percent at the start of this year, reported Johnson-Perkins & Associates Inc. That occupancy rate was slightly higher than a year earlier.

Retailers large and small keep a close eye on population growth as they gauge the need for new stores. Still, the 0.2 percent dip estimated by Hardcastle probably won’t mean much to them, said Ken Mattison, a senior vice president in the retail division of Coldwell Banker Commercial Clay & Associates in Reno.

“The losses are primarily those in the unskilled labor, skilled tradesman and seasonal worker categories who left to find employment outside Washoe County,” Mattison said.

He said, too, that population growth is only one factor that drives retail development and fills spaces in existing centers.

Franchise operators, too, are spreading slowly in the weak economy.

Researchers for the State Department of Employment, Training and Rehabilitation said job losses — the key element in population declines — appear to have continued in Washoe County early in 2012.

The Reno-Sparks metropolitan area posted an estimated loss of 400 jobs in January. In Carson City, meanwhile, recent job losses mean that total employment stands at the same level as it did in 1997, said Bill Anderson, chief economist for the state employment department.

Carson City’s population stood at 56,066 in the middle of 2011, the demographer estimated. That’s up 0.4 percent from a year earlier. Anderson said his research team expects slow to moderate growth in employment statewide in coming months because employers still are trying to decide the strength of the economic recovery.

Strength in the mining industry, meanwhile, continues to contribute to solid population growth in the rural counties of northeast Nevada, Hardcastle said.

Population in those areas grew an estimated 1.5 percent from mid-2010 until mid-2011.

Statewide, he estimated that population is the most recent year grew by 0.6 percent (roughly 17,000 people). That’s about the same as the growth rate a year earlier.

He said there’s little evidence that jobless folks are loading rental trucks in large numbers to seek better prospects elsewhere.

“The data doesn’t support that large numbers of people are moving out of the state at this time,” Hardcastle said.