Data Shows Largest Exodus From L.A. This Century : Demographics: Loss of 68,000 residents is linked to economic downturn and last year’s riots, city planners say.

After a decade of near-record growth, the population of Los Angeles fell 68,000 from 1991 to 1992, the city’s largest annual decline and only the third time this century it suffered a net loss of residents over a year, according to population estimates released Friday.

City planners said the decline can be linked to continuing economic troubles as well as the riots following the verdicts in the Rodney G. King beating trial last year.

“Economics are probably the major explanation and there’s the possibility the disturbances could be used to explain some of it,” said Jeff Beckerman, a city demographer who prepares annual population estimates based on residential vacancy rates, utility hookups and school enrollments.

Job losses in the city have probably accelerated the movement of older residents to other areas and slowed the number of younger, incoming residents, Beckerman said.

An estimated 3,462,403 people lived in Los Angeles in October, 1992, down 67,982 from the previous October for a decrease of about 2%, the city report said.

Despite the overall decline, city planners show growth in the north San Fernando Valley, which has had an estimated population rise of 0.7% since 1990. The communities of Arleta and Pacoima in the northeast Valley showed the fastest growth during that time, with population increasing nearly 6%.

The largest declines in population were recorded in central and southern portions of the city, which have lost about 1.4% of their population, an estimated 23,400 residents, since 1990, the city report said. The Westside, Hollywood and the southern portion of the San Fernando Valley all showed declines.

Mayor Richard Riordan said in a prepared statement: “I have not had an opportunity to completely review the report in detail, but the findings clearly reinforce the fact that we need to turn Los Angeles around and address public safety, jobs and the economy to make L.A. a more desirable city to live in.”

The economic downturn has also pushed vacancy rates up, and in some parts of the city it is clear that many residents are being forced to share increasingly crowded apartments and homes, the city report shows.

In the southeast parts of the city, for example, the population is increasing along with the number of vacant housing units.

The population of Los Angeles has increased every year during this century with the exception of 1974, when it fell by 3,281, and 1973, when the city lost 25,207 residents.

Beckerman said it is possible that the population decrease may continue.