During the past decade, the state's inland areas grew as Californians moved beyond the pricey coastal region. But demographers say that migration appears to have slowed in recent years after the economy slumped.

Of the state's most populous counties, Riverside County grew the most. Its population jumped 41.7 percent, making it the state's fourth largest county.

California's inland counties also become more diverse. For example, Riverside County is now 46 percent Latino and San Bernardino County is 49 percent Latino, up from 36 percent and 39 percent a decade ago, respectively.

African-Americans also moved to outlying areas such as Riverside County and San Joaquin County, leaving counties including Los Angeles, Alameda and San Francisco, the data shows.

Hans Johnson, director of research at the Public Policy Institute of California, said the growing diversity in suburbia might eventually ease the political divide between a largely Democratic coastal region and more Republican inland California since Latinos are more likely to vote Democratic.

"The caveat here is that many Latinos are immigrants and not naturalized citizens and therefore not eligible to vote," Johnson said. "That is why the voting patterns will lag the demographic changes, but they are coming."

While more than a quarter of Californians still live in Los Angeles County, the county's population only grew 3.1 percent over the decade. San Diego County grew 10 percent to become the state's second most populous county with 3.1 million people, overtaking Orange County, which has 3 million people.

The data will be used by a state commission to redraw congressional and state legislative districts in California.

Demographers questioned whether the data might reveal more than population trends in California.

Some suggested Californians also might be changing the way they view their ethnic identity and wondered whether people are more likely to report they are Latino now than a decade ago, which could account for some of the decline in non-Hispanic whites.

"Maybe some people who have one Hispanic parent weren't Hispanic 10 years ago and now they are," said John Pitkin, a demographer in Cambridge, Mass. "I am sure there will be a lot of studies in the coming year trying to figure that one out."