Arizona’s population grew by nearly 100,000 in 2015, driven largely by growth in Maricopa County which saw the second-largest increase among counties in the nation, according to new Census Bureau estimates.

The bureau’s 2015 population estimates for counties and metro areas also said that Maricopa finished first in the nation for net domestic migration growth for the year, or people moving in from other areas of the country.

The growth brought the state’s overall population to an estimated 6.83 million residents as of July 1. Most of the growth was in Maricopa, which gained 77,925 residents from the year before. About half of those, or 37,670 were attributed to domestic migration.

But Maricopa was not the only county to see an increase in 2015, as 10 of the state’s 15 counties posted gains that year.

Experts said they were not surprised by the state’s growth, which they attributed to the usual lures of good climate, low taxes and affordable cost of living, particularly when compared to neighboring California.

The increases can be seen in businesses like the state’s real estate industry, officials said.

“There has absolutely been an uptick in the West Valley,” said Roger Nelson, chief executive officer of WeMar, the West Maricopa Association of Realtors. “There’s also been additional growth in the developments that were stalled during the (economic) downturn and are now being revisited.”

“We’re in a pretty stable market,” he said of the real estate industry, pointing to builders in the West Valley that have been coming “back into play to keep up with the demand” for housing, as an example.

Statistics from the Arizona Department of Real Estate appeared to back that up, showing a 3.67 percent increase in real estate licenses from last February to this February, according to Assistant Commissioner of Operations and Legislative Affairs Louis Dettorre.

“Additionally, the ADRE (Arizona Department of Real Estate) has seen an increase in public report amendment applications by 19 percent from the same month last year, which reflects developer and homebuilder activity,” Dettorre said in an email.

Some analysts believe much of the gain in Arizona comes from neighboring California.

“Arizona is much cheaper to live in than California,” said Mike Orr, real estate analyst and founder and CEO of the Cromford Report which provides analysis of the Arizona real estate market.

Even though Arizona’s rental prices are on the rise, they are still cheaper than California’s and draw a lot of that market, Orr said.

University of Arizona geography Professor David Plane echoed Orr.

“There is a huge price difference between Arizona and California, and affordable housing is a big attraction with moving,” said Plane, whose studies include demographics.

He said the relationship with California has helped drive the Arizona economy for the last several years.

Plane said another factor that contributes to the state’s population growth is Arizona’s reputation as a “mecca for retirement” – which may also play a part in Maricopa County’s role as a leader in domestic migration gains.

“Old migration is more demographically effective,” he said of retirees moving to the state, “because oftentimes it is their final destination and that adds to the potential to have a lot of net migration.”