(FORTUNE Magazine) – Whatever may be happening to the merely rich, the extremely rich are getting a little richer. This year the average billionaire's net worth is $2.7 billion, just $100 million more than it was in 1990. In addition, there are more people in the ten digits this year than ever before. There are 202 billionaires, up from 182 in 1990, with 41 new arrivals and 26 departures. An increasing number of billionaires -- whom FORTUNE defines as individuals and nuclear families with a personal net worth of at least $1 billion as of mid-1991 -- prompts the comforting thought that more people are getting richer, but the truth is that the reporting for each list always uncovers a few billionaires we missed previously. By and large, the super-rich don't advertise, and with enough money to gratify their passion for anonymity, they can be hard to locate. You won't find Colombian drug lords or Mafia godfathers or Saddam Hussein on this list, because we confine it to people whose wealth can be traced. Saddam may indeed be worth billions from looting the Iraqi treasury, as has been widely reported, but his net worth is impossible to prove. The world's richest man remains the Sultan of Brunei, whose extensive investments in bonds, gold, and real estate have flourished. This year the Sultan is worth $31 billion, up from $25 billion. The second-biggest fortune belongs to Sam Walton and his family. Their net worth grew to $21 billion when Wal-Mart stock rose 31%. But don't look to Mr. Sam for a lesson in riotous, lucre-filled living. He still works out of a drab two-story office building in his hometown of Bentonville, Arkansas, and attends potluck suppers at the local Presbyterian church. The Sultan, on the other hand, sure knows how to show a kid a good time. For his nephew's ninth birthday last November, he threw a party with a Ninja Turtles theme at London's elegant Claridge's hotel. The bill was said to be $950,000. A glance at the great fortunes of 1991 reveals that the road to astronomical riches has often been down the aisle of a store -- usually a department store. There are nine department store fortunes on the list, seven grocers, and 28 retailing piles altogether, with Wal-Mart at the top of the heap. Real estate is a close second with 22. Together real estate and retailing account for nearly a quarter of the billionaires. The next biggest chunk, 16, comes from media companies, while food or beverage concerns produce 14. The remaining Midases earn their keep from a golden touch with businesses including automobile manufacturing, banking, cosmetics, construction, oil, shipping -- and prudent marriage. As usual, the U.S. has the most billionaires, 60. Back on the list after a three-year hiatus are Donald and Doris Fisher, the San Francisco couple who founded the Gap in 1969. The stock rebounded and so did they. Former federal prosecutor Samuel Heyman is a newcomer. He gained control of chemical manufacturer GAF in 1983 after an extended proxy fight, and engineered a management buyout after the 1987 stock market crash turned it into a bargain. He now owns 85% of the company and is worth an estimated $1.5 billion. For the first time ever, Mexicans (two of them) and South Koreans (five) appear on the list, evidence of their countries' growing economic vitality. Son of a Lebanese immigrant, Carlos Slim Helu bought undervalued Mexican stocks in the early 1980s, when the peso was falling faster than most Latin American cabinets. Then, over the past five years, he watched his fortune rise with the bolsa. Emilio Azcarraga Milmo's Televisa holds a virtual monopoly on Mexican private broadcasting and exports Spanish-language soap operas to all of Latin America. Sports-crazed gringos may know Azcarraga better as the man who bankrolled the National Sports Daily, which folded in June and lost him $100 million. South Korea's billionaires are the heads of five mighty conglomerates. Among them are Chung Ju-Yung of Hyundai and Ku Cha-Kyung of Lucky Goldstar. Germany, with its powerful economy, takes the prize for the largest number of first-time billionaires, nine, giving that nation 23 overall. In Europe only Switzerland has as many -- and it is often a tax haven for fortunes made elsewhere. Germany is also Heimat to the youngest richling, Prince Albert von Thurn und Taxis, 8, who came into his fortune when his father, Johannes, died following a heart transplant in December. Albert's mom, Gloria, the formerly high-living handful known as Princess TNT, is now rapidly learning about finance to help manage her son's inheritance until he comes of age. GONE from the list are a few old friends. It is impossible to estimate the wealth of Sheikh Jaber Ahmed Al-Sabah, ruler of Kuwait. He could be worth $15 billion or several hundred million. During his country's occupation by Iraq, Kuwaiti oil wells began burning, and the Sheikh probably also dug deep into his own purse to help refugees. He may be entitled to a refund from the national treasury. Then again, maybe not. There was a huge outcry immediately after Kuwait's liberation when he brought Irish linen and sterling silver cutlery into his temporary palace -- before emergency food provisions had been distributed or the shattered infrastructure repaired. Sheikh Jaber has promised free elections in 1992, and elected officials may be inclined to more closely scrutinize the line between what is his and what is Kuwait's. Queen Beatrix of the Netherlands, whose fortune derived from ten Dutch guilders split among the heirs of William I of Orange after his murder in 1584, is also off the list. The State Information Agency of the Netherlands had routinely refused to comment on the Queen's wealth, known as the ''secret of Soestdijk.'' But this year the agency reported that, as a tax-saving measure, the assets of the House of Orange had been transferred to four national foundations over which the Queen has limited control. The property she owns outside these trusts does not add up to $1 billion. Joining her in exile are Harold Simmons and Rupert Murdoch, both victims of wilting stocks. Simmons, who owns most of Valhi Corp., a holding company for sugar, chemicals, timber, and fast-food concerns, finally gave up trying to take over Lockheed last March. Murdoch's News Corp. tumbled when the media business declined, forcing the press lord to restructure the company's heavy debt load and sell off assets. There's no need to pass the plate on behalf of the drop-offs; they've still got hundreds of millions. Even a cursory study of billionaires demonstrates one old saw about money: Them as has, keeps. This is particularly true of those who earn rather than inherit their money. First-generation billionaires, on the whole, have little taste for luxury and are not the bons vivants they could afford to be. While his son Edward DeBartolo Jr. dresses in Italian suits and drives luxury cars, shopping-mall developer Edward Sr., 82, works 14 to 15 hours a day, seven days a week, and is said to dine nearly every night on the same dish -- veal with peppers -- at the same restaurant, Paonessa's in Youngstown, Ohio. Curtis Carlson, 77, who owns Radisson Hotels International and the restaurant chain TGI Friday's, gave up golf because he didn't like the time it kept him away from work. He switched to tennis, so he can build up a good sweat in three sets and then head back to the office. Brazilian industrialist Antonio Ermirio de Moraes toils 72 hours a week at his austere headquarters in Sao Paulo and wears suits he must have slept in, while Turkish entrepreneur Mehmet Emin Karamehmet has no hobbies, doesn't care for food, and never travels unless on business. THE CURIOUS exceptions to rampant billionaire workaholism are the ''industrious'' Japanese. Though they all work very hard, five of Japan's 12 billionaires profess a passion for golf and play it whenever they can. Kichinosuke Sasaki, a real estate developer, makes time to bathe in onsen, Japanese hot springs, while ball-bearing king Hiroshi Teramachi savors biographies of prominent historical figures. Pharmaceutical magnate Shoji Uehara loves impressionist painting and heads for France at every opportunity. Real estate investor Rinji Shino, who is building an airport tower in Osaka, collects Ukiyo-e woodblock prints depicting scenes of everyday life in Japan from the 17th to the 19th centuries. Says Hiroshi Yamauchi, the man behind Nintendo: ''My motto is to live in a manner so I always have enough time to relax.'' You don't have to be a billionaire to afford that.

BOX: CONTENTS

INTRODUCTIONAL TO THE LISTS 42 BILLIONAIRESSES 52 THE LISTS 59