Typically Atypical San Francisco : Census: The city’s diversity is reflected in its changing ethnic makeup and in people’s lifestyles. Anglos no longer are a majority, and only 20% of the households include children.

About 100,000 runners traversed the city Sunday morning in a yearly frolic--part footrace, part street circus--known here as the Bay to Breakers. Live TV and radio covered the goings on, which followed two days of parties and a contest for the most witty and wild costumes.

For some people, the mix of athleticism and zaniness is a quintessential San Francisco celebration, a daytime cousin of the Black and White Ball earlier this month. At that affair, about 13,000 party-goers in black-and-white get-up from tuxedos to shorts paid $175 each to drink, dance and munch hors d’oeuvres on behalf of the symphony.

But it would be hard for any event to capture this many-flavored city, especially a 7.5-mile race derided in some San Francisco circles as the ultimate yuppie event. The runners are mostly white, and the winners get new BMWs.

Fewer Anglos live in San Francisco than at any time this century, last year’s U.S. census found. At 47% of the population, Anglos--”non-Hispanic whites” to the Census Bureau, a category that includes the city’s old-line Italians and Irish--are now the largest minority in a city with a dozen distinct cultures.

The census found that Asian-Americans made up 28% of the city’s population, and they no longer lived only in enclaves such as Chinatown. But the story of San Francisco’s diversity goes beyond ethnic groups, into the way people are choosing to live.

Only 20% of San Francisco households include children, fewer than one-fifth of adults under 45 own their home, and nearly 100,000 people--almost one in 7 residents--live with a friend, lover or roommates they are not related to by blood or marriage. About 17% of residents live alone, double the rate for the rest of California.

“San Francisco has pioneered a sense that no one type represents the average San Franciscan,” said Kevin Starr, a historian and longtime resident now teaching urban and regional planning at USC.

San Francisco has known diversity since its time as a Gold Rush seaport, when author Richard Henry Dana was overwhelmed by the mix of peoples walking the wild city’s streets. Today’s mix, unique among large U.S. cities, is displayed at events such as next weekend’s Carnaval, arguably a more representative festival than Sunday’s Bay to Breakers race.

Carnaval is a two-day street festival of ethnic food and music from samba to calypso, held the past 11 years in the Mission District. The party’s topper is the city’s biggest annual parade, which wends through the district, an old Irish and Italian area that has become a melting pot of ethnicity and lifestyles.

“Carnaval is a lot of fun, a lot of music and dancing,” said Sara Ortiz, a Mission District waitress.

The diversity is also reflected in other events that were scheduled over the weekend, but drew far less attention than the footrace. KPFA, a progressive FM radio station, was to air African music and discussions all weekend to mark the birthday of Malcolm X.

In the Mission District, at the Women’s Building on Valencia Street in what may be America’s only lesbian neighborhood, a talk was planned Sunday night about the portrayal of gays in humor. One of the speakers, gay comedian Tom Ammiano, was elected last year to the San Francisco school board.

A colorful display of San Francisco’s mix came earlier this month--a Sunday morning funeral procession through the city for Yin Doon Wong, a leader of the Six Companies, the hierarchy of families and property holders that has dominated Chinatown for more than a century.

As the white hearse stopped at shops across the city, incense was burned and tea spilled on the ground in a Chinese ritual. Mayor Art Agnos, the San Francisco Examiner reported, said at the funeral at Chinese Cemetery in nearby Colma that “there are those who say Mr. Wong only had to nod his head and things began to happen.”

In the 1980s, the Chinese, who are 62% of San Francisco’s Asian community, fanned out of Chinatown to settle across the city, the census found. In North Beach, an Italian area, and the working-class Irish Sunset district, Anglos were the majority a decade ago but now are about even in numbers with Asian-Americans.

When the country was on the verge of war in 1940, Anglos made up 95% of San Francisco’s population. The city began to attract ethnic minorities after World War II, and by the 1980 census a Anglos had slipped to 53% of the population.

In the latest count, the 47% share of the population that is Anglo numbered 337,118. The last time the census found fewer Anglos in the city was in 1900, when the Census Bureau still asked questions about how many rifles and horses a household owned. The city is also 14% Latino and 11% black, the 1990 census found.

Almost every district in the city--including the richest--shared in the 40% jump in Asian-American population, driven by a boom in immigration from Hong Kong, Taiwan and the Philippines in the 1980s.

On Mission Street, the main boulevard in the Excelsior area near the southern edge of the city, the Sons of Italy hall now shares a block with Filipino groceries selling lumpia and jackfruit. The Italian-American Social Club and the Valente, Marini, Perata & Co. funeral home are reminders that the street was once an Italian colony.

Nearby, the Slavonic Mutual and Beneficial Society and the street names--Edinburgh, Russia, Italy, Lisbon--reflect the European culture that grew up here a half century ago.

In the census a decade ago, Anglos were the largest ethnic group in the Excelsior. Now the district is 36% Latino, 32% Asian-American and 28% Anglo with a smattering of others. The Bay to Breakers race did not get much attention here.

“There’s nothing there for me,” said Wendy Louie, shopping in a Chinese-run store on Geneva Street. “I don’t even run.”

The Bay to Breakers traces its roots to 1912, when a cross-city race was staged to help promote a World’s Fair. Sponsored by the Examiner, it is billed locally as the world’s largest and silliest footrace.

“Cities need these occasions of pageantry, when everyone in the city can go out and look at themselves,” Starr said.

For a city of such diversity, there is little overt racial tension in San Francisco, he said. Starr also said white flight to the suburbs here is due less to racial fears than to sky-high home prices.

“White people in the San Francisco area have a very low sense of being embattled. You don’t hear a lot of talk about ‘the minorities taking over,’ ” Starr said.

Anglos, whose numbers in the city fell by 5% in the latest census, are not the only ones leaving. The black population of San Francisco dropped by 11%--leaving 76,000 fewer blacks in San Francisco than 10 years ago.

Most of the departed can be found in the suburbs that have begun to push the Bay Area’s outer limits into the San Joaquin Valley, the wine regions of Sonoma and Napa counties, and south from San Jose.

Unlike most American suburbs, those around San Francisco almost mirror the city’s ethnic diversity. Asian-Americans are more likely to live elsewhere in the Bay Area than in San Francisco, the census found.

Just south of San Francisco, the white postwar suburb of Daly City--ridiculed for its “ticky tacky” homogeneity in the 1960s song “Little Boxes” made popular by Malvina Reynolds--now has the highest concentration of Asian-Americans in Northern California. Only Monterey Park and Cerritos in Southern California have a higher percentage of Asian-Americans than Daly City’s 42%.

“The scale at which the suburbs have become racially mixed is really astounding,” said Richard LeGates, director of the urban studies program at San Francisco State University, adding that the Bay Area has become “a new kind of American metropolis.”

The city’s 11-member Board of Supervisors includes two blacks, one Latino and one Asian-American. Last fall, two longtime lesbian political activists, Roberta Achtenberg and Carole Migden, were elected to the board.

This month, the board unanimously offered health insurance to the unmarried partners of city and school workers. About 10,000 people, about half of them gay men or lesbians, are expected to benefit.

Agnos, who is up for reelection in the fall, has drawn opposition from several directions. Former Police Chief Frank Jordan, running as a moderate alternative to the liberal Agnos, was pictured this month on the front page of the Irish Herald and is seen by many as the candidate of the older neighborhoods.

Former Sheriff Richard Hongisto, now the tax assessor, is attacking from the left and has the endorsement of the most prominent gay politician, Board of Supervisors President Harry Britt.

The most prominent of the ethnic minority candidates is Supervisor Tom Hsieh, a Chinese-American who is raising money in Asian communities around the Bay Area. Hsieh, a conservative, is running against the tide in a city so liberal it gave Democrat Michael S. Dukakis 72% of the vote in the 1988 election, which President Bush won elsewhere by a landslide.

Agnos enjoys strong backing from Chinatown’s leaders, an advantage that Starr said has become valuable in modern-day San Francisco.

“No one can become mayor without a Chinese strategy,” Starr said.