STATE'S POPULATION GROWTH SLOWING : EXPERTS SAY CALIFORNIA BEHIND U.S. AVERAGE.

Byline: David Westphal Scripps-McClatchy Western Service

When they call the roll at the turn of the century, California will find itself in a most unaccustomed place - aligned with a group of slow- to average-growth states.

For the first time ever, census experts say, California's 10-year population growth rate will be below the national average, a result of a huge migration of job-hunting residents out of the state during the 1990s.

New projections by the U.S. Census Bureau put California's 2000 population at 32.5 million, an increase of 8.8 percent since the last census. The nation as a whole, by contrast, is expected to be up 10.1 percent.

Based on those numbers, the Census Bureau projects that California will fail to gain a seat in the House of Representatives for the first time since 1920, when seats were frozen for all states.

Exactly where California, the nation's largest state, will emerge at the end of this decade is anyone's guess. State officials believe California's population turnaround is already under way and that the state's growth likely will beat federal projections.

The chief of the Census Bureau's projections division, Gregory Spencer, acknowledges that estimating California's future population is his office's toughest task. ``It's not like projecting North Dakota,'' he says. ``It's so big and so volatile; it's easy to be off.''

But, for better or worse, all sides agree the slower-than-average expansion of the 1990s won't last. Between 2000 and 2025, California is projected to return to its fastest-in-the-nation growth rate - up 51 percent to just shy of 50 million people.

Over that period, the Census Bureau data point to a rapidly changing California, in which two-thirds of the population is made up of African-Americans, Latinos and Asians; where the proportion of elderly is one of the lowest in the nation; and where the number of school-age children expands rapidly.

The Census Bureau's report is not a prediction of the future. Rather, it's an extrapolation based on long-term trends such as birth and death rates, international immigration, and movement to and from other states. From this vantage point, population experts say, the massive migration out of the state this decade - approaching 1 million people a year - is an aberration unlikely to be repeated.

It's certainly new territory for California. Since 1940, California has grown four times faster than the United States as a whole. Only in the post-Gold Rush, late 1800s did the country's population growth come close to matching California's.

But the combination of powerful economic forces leveling the state's economy in the early 1990s changed all that.

Last week, the Census Bureau announced that California's population on July 1 had reached 31.9 million - up 6.6 percent since 1990. During the 1980s, by contrast, California's population was growing twice as fast.

The big change is the large contingent of Californians leaving the state. According to the Census Bureau, California's net population loss because of movements in and out of the state reached 1.8 million through the first six years of the decade, and could exceed 3 million by 2000.

The departure of California residents is what's fueling the expansion of places like Nevada and Arizona, the fastest-growing states in the nation, according to census officials. Seven of the 10 biggest-growth states are in the West, and it's in part because of the California exodus, Spencer said.

Earlier this decade, unemployment hit 9 percent in the state as retrenchment in the defense industry combined with other economic forces to force Californians to look elsewhere for work. In one year alone, July 1993 to July 1994, the number of people leaving the state exceeded the new arrivals by more than 400,000.

Only the continuing flow of international immigrants - roughly 250,000 a year - has kept California from zero population growth.

Anecdotal data suggest the people leaving have been younger than average and disproportionately white. Census projections indicate that California's 18-24 age group will decline 8.4 percent between 1990 and 2000. Nationally, the age group is projected to be down only 2 percent.

The numbers also suggest that those leaving California are about 70 percent white - significantly higher than their representation in the population. As a result, the number of non-Latino whites in California is projected to fall 8.9 percent in the 1990s, to 15.6 million.

State demographer Mary Heim, however, notes that there's been a net loss of California Latinos and African-Americans to other states, as well.

Heim also contends the Census Bureau inaccurately assumes that the unprecedented flight of Californians to other states will continue for a number of years.

``The outmigration will end soon, if it hasn't already stopped,'' she said.

In any case, both state and federal demographers believe the 1990s will be seen as a historical blip running counter to California's long trend of explosive growth. Between the turn of the century and 2025, bolstered by a growth rate more than twice that of the nation as a whole, California would reach 49.3 million people, according to the projections.

At that point, the numbers suggest, California would have:

Fifteen percent of the nation's population, compared to the current 12 percent.

The second-lowest percentage of elderly in the country, at 13 percent. Only Alaska would rank lower.

Rapidly expanding Latino and Asian populations. Latinos would make up 43 percent of the population and Asians 17.4 percent. Non-Latino whites would fall to 33.7 percent; African-Americans would also decline, to 5.4 percent.