Asians, Latinos Surge in U.S. Growth Rates : Census: Their numbers rose far faster than other groups in the 1980s. Immigration and high birth rates are factors. Black increase is double that for whites.

Asian and Latino population groups in the United States grew far faster than others in the 1980s, their numbers swelled by a combination of immigration and high birth rates, the Census Bureau said Thursday.

The nation’s Asian population grew by 70% between 1980 and July 1, 1988, the bureau said, with about two-thirds of the increase due to immigration.

During the same period, the Latino population grew by 34%, with half of the increase stemming from immigration and the other half from high birth rates.

The surging numbers of Latinos and Asians have already had a powerful impact in California, but nationwide, these two groups still make up a relatively small percentage of the overall population. In 1988, Latinos made up 8% of the nation’s total and Asians 2.7%, the bureau reported.

The number of blacks grew by 12.7% during the eight years, double the growth rate for non-Latino whites. The 30.3 million blacks made up 12% of the nation’s population in 1988.

The white population grew by 6.2% during the same period.

But 76% of Americans are still non-Latino whites. The total number of whites, including Latinos classified as white, actually grew by more than the combined increase in blacks, Latinos, Asians, Eskimos and American Indians.

In 1988, there were 12.2 million more whites than eight years before, while the faster-growing minority groups added 11.4 million to the nation’s total during the same period.

Each year, the Census Bureau reports on the changes in the U.S. population by age and race, or ethnic group. The figures released Thursday were not broken down by state or metropolitan region.

However, earlier reports have shown that the impact of the Asian and Latino population has been concentrated in California.

Based on 1985 estimates, statisticians estimated that 38% of the nation’s Asians lived in California.

“If you put California and Hawaii together, you get essentially half the Asian population,” said David Word, a Census Bureau statistician. California accounted for 33.5% of the nation’s Latino population in 1985, he said.

The census report also quantifies what advertisers and marketers have already known: The post-World War II baby boom generation is getting older, and most will soon be “40 something” rather than “30 something.”

The 35-44 age grouping was the fastest-growing segment between 1980 and 1988, increasing four times faster than the overall population.

While the baby boomers are “in the later ages of parenthood,” the report notes, the number of young adults moving into the parenting years has been shrinking and will continue to do so. In the 1980s, the number of persons from 18 to 24 dropped 11%.

The report also said:

--The median age of Americans was 32.3 in 1988. This number has been inching up since 1970, when it stood at 27.9.

--Slightly more than 12% of Americans were over age 65. This is an increase of only a single percentage point since 1980, the report said, and is due mostly to the fact that persons are living longer.

--The high school-age group of teen-agers from 14 to 17 shrank by more than 13% in the decade. The number of high schoolers should remain constant early in the 1990s and grow toward the end of the decade.

--Despite the aging of the baby boomers, the birth rate in 1988 rose slightly again to 15.9 per 1,000 population. This rate hit a low of 14.5 per 1,000 in 1976 and has been edging up since then.

--The immigration rate, though still high, is below what it was at the beginning of the decade. In 1988, the “net immigration rate” was 2.7 per 1,000 residents, down from 3.7 per 1,000 in 1980.