As unemployment numbers remain markedly high, the number of high-net worth individuals in the U.S. continued to increase in 2010, according to Capgemini’s 2011 U.S. Metro Wealth Index.

The index, released on Tuesday, found that the number of high-net worth individuals (HNWI) in the top 10 U.S. metropolitan areas jumped by 7.3% in 2010, with New York, Los Angeles, and Chicago highest on the list and Houston recording the highest total growth rate of 9.6% taking over the No. 8 slot from Detroit.

Although the number of high-net worth individuals increased in 2010, the growth in HNWI was down compared to 2009 when growth the number shot up 17.5% after declining sharply in 2008. Nonetheless, the number of HNWI in the U.S. surpassed the 2007 pre-crisis levels.

“We saw many HNWIs – not just in these metropolitan statistical areas, but globally – taking on more calculated investment risks and shifting assets into what we consider more aggressive asset classes in a continued effort to recoup some of the losses they faced as a result of the financial crisis,” said William Sullivan, Head of Global Market Intelligence, Capgemini Financial Services, in a press release. “An important contributor to the increase in HNWI population we saw in these areas was the continued rise in U.S. equity and commodity markets, which led to many investors seeing the value of their investments grow.”

Meanwhile, 2010 was the second year in a row Houston moved up the Index, having ranked 10th on the list in 2008.

“Houston has been a strong growth story over the past two years, having been able to recover from the largest percentage fall of HNWIs in 2008,” said Sullivan. “In addition to one of the lowest unemployment rates among the ten MSAs, Houston’s economy has significant exposure to the oil and gas industry, which may have contributed to the growth in Houston’s HNWI population.”

Understanding where HNWIs live and work is critical for wealth management firms in terms of targeting resources effectively and understanding the growth of potential markets and client segments, as well as insights on future trends.