$1 billion: The minimum amount now needed in the bank to qualify for Forbes magazine's exclusive list of the 400 richest Americans.$1.25 trillion: The total worth of the top 400. The dollars have been stacking up over the last 12 months, exceeding last year's total of $1.13 trillion.$53 billion: Microsoft founder Bill Gates' estimated fortune. Gates has occupied the top spot for the last 13 years. Businessman Warren Buffett maintains his number two slot with $46 billion.$1 million: The amount earned per hour by casino magnate Sheldon Adelson, who leapt into the number three slot.$395 million: The amount of money lost over the past year by Martha Stewart, who fell off the list completely.90: The number of people on the rich list 400 who live in California. Another 44 live in New York City.