Millionaires are back. The number of individuals worldwide with $1 million or more in assets aside from their residence grew by 8.3% to 10.9 million in 2010, topping pre-crisis 2007 levels, according to the World Wealth Report released Wednesday.

The United States remained home to most of what the financial services industry calls high-net-worth individuals. The ranks of U.S. millionaires grew from 2.9 million in 2009 to 3.1 million in 2010 -- about 1% of the population.

The study, conducted by Merrill Lynch Global Wealth Management (BAC) and Capgemini, found that women and investors 45 and younger helped propel the surge. Female millionaires increased from 24% to 27% of the count since 2008. The percentage of younger market players increased from 13% to 17%.

Investors in general began moving away from cash holdings and deposits into riskier equities, and that paid off, said John Thiel, head of U.S. Wealth Management for Merrill Lynch Global Wealth Management. The redistribution, he added, was further indication that market confidence has picked up since most of the world landed in the economic dumpster in 2008.

The 23 brokerages worldwide that participated in the survey predicted that interest in equities would continue to rise while reliance on real estate to build wealth would fall. (We suspect that a Century 21 survey might produce a different forecast.)

Overall, 53% of the world's millions and its millionaires are concentrated in the United States, Japan and Germany, according to the study.

Regional traumas such as the Japanese earthquake, tsunami and nuclear meltdown replaced collective global turbulence in 2010 -- another reason for the steady growth of the affluent, the study said. The pockets of disturbance allowed for more stability overall.

Thiel said the findings were "not surprising." "It's quite refreshing that we're plodding along."

The news was even better for the filthy rich. The number of ultra-high-net-worth individuals -- those with $30 million or more in assets -- grew by 10.2%.

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