The 100 wealthiest people in the world made themselves even richer by adding $241 billion to their collective net worth in 2012, according to a daily ranking of the wealthiest individuals.

Bloomberg Billionaires Index calculated that the net worth of the world's top 100 stood at $1.9 trillion when the market closed on Dec. 31, 2012. Of the people who appeared on the final list for 2012, only 16 registered a net loss for the 12-month period.

The Index determines the world's wealthiest people based on market and economic changes and Bloomberg News reporting. Net worth figures are updated every business day at 5:30 p.m. in New York and the monetary values are listed in U.S. dollars. 

Amancio Ortega, 76, who founded retailer Inditex, gained more than anyone else on the Bloomberg Billionaires Index for 2012 - his fortune increased to $57.5 billion, a gain of $22.2 billion in one year. As a result, shares of the Spaniard's Inditex, which operates the Zara clothing line, rose 66.7 percent.

Though Ortega was the year's biggest gainer, Carlos Slim, the telecommunications tycoon who controls Mexico's America Movil, remained the world's richest person for the entire year. The 72-year-old's net worth rose $13.4 billion (21.6 percent) through Dec. 31, making him the second-biggest gainer by dollars. 

U.S. software mogul Bill Gates, 57, ranks second on the list, behind Slim by $12.5 billion. The Microsoft co-founder added $7 billion to his net worth. Warren Buffett, 82, went from third to fourth place; he lost his title as the world's third richest man to Ortega. IKEA founder Ingvar Kamprad, 86, ranked No. 5 with a $42.9 billion fortune. His net worth rose 16.6 percent in 2012.

Rupert Murdoch's wealth jumped by $2.9 billion to $10.7 billion in 2012 thanks to a 44 percent increase in the value of his News Corporation shares. The company bounced back from the 2011 phone-hacking scandal that resulted in the closure of the News of the World in Britain. On the other hand, Australian Gina Rinehart dropped in ranking and came out as No. 39 on the Bloomberg Billionaires Index for 2012 after her $18.6 billion fortune fell 8 percent, or $1.6 billion. The Daily Examiner noted the loss was "partly due to softer iron ore prices last year, and partly due to losing investments in media companies including Ten Network and Fairfax Media."