WASHINGTON, Dec. 21 (Xinhua) -- The U.S. population grew 9.7 percent over the last decade, the slowest growth since the 1930s, the Census Bureau said on Tuesday.

As of April 1, 2010, the country's total population rose to 308. 7 million, up 9.7 percent from 10 years ago, the second lowest pace of the past century, Census Director Robert Groves said while announcing the findings at a news conference.

The once-in-a-decade population count shows that the South and the West added the most populations over the last decade, indicating states in the two regions are on track to make some gains in the reapportionment of the House seats.

Population in the Southern states rose 14.3 percent since 2000, the largest in all four regions. The West had a growth rate of 13. 8 percent. The Northeast had a 3.2-percent growth while the Midwest had 3.9 percent.

In absolute terms, Texas gained the most people, up 4.3 million to 25.1 million. In terms of percentage of the 2000 population, Nevada gained the most with a growth rate of 35.1 percent.

The census results have been closely watched as they serve as the basis for the redistribution of congressional seats among states. The data also help determine how more than 400 billion dollars in federal funds are distributed to tribal, state and local governments every year -- including funding for schools, roads, healthcare and other critical programs, according to the bureau.

Based on the latest head count, eight states will gain congressional seats and ten will lose them. The biggest winners are Texas, which will gain four seats, and Florida, which will gain two. New York and Ohio are the biggest losers, each losing two seats in the House.