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NEW YORK (TheStreet) -- Another 1.1 million Americans officially joined the millionaire's club in 2013, bringing the total number of millionaires in the country to 7.1 million.


Another 1.1 million Americans officially joined the millionaire's club in 2013.

That brings the total amount of millionaires in the U.S. to 7.1 million, the most in any developed country.  Overall, wealth in the U.S. grew by 16.3% in the last year.

And it's picking up steam.  Households worth $1 million or more are projected to grow by at least 7.7% a year through 2018.  While the richest are getting richer, too.  Households with assets of $100 million or more held $8.4 trillion in wealth in the U.S. in 2013, which is a gain of nearly 20% over the year before.  Those households are projected to hold $13 trillion in wealth by the end of 2018 -- accounting for 6.5% of the total wealth in the world.

The primary catalyst for the wealth creation is booming equity markets as well as expanding prosperity in developing economies.

China gained nearly as many millionaire households as the U.S. last year, rising to 2.4 million from 1.5 million the year before, according to the Boston Consulting Group.

The Asia-Pacific region excluding Japan posted the strongest growth in private wealth in the world, at 30.5%, and that region is expected to pass Western Europe as the second-wealthiest region this year, ultimately taking over the U.S. as the wealthiest region in the world by 2018.

In New York, I'm Brittany Umar for TheStreet.

-- Written by Brittany Umar in New York.