The U.S. population jumped 9.7 percent over the past ten years, reaching almost 309-million people as of April 1, 2010, according to the U.S. Census Bureau.

California was the most populous state with more than 37-million residents; Wyoming was the least populous, with about 560,000.

Texas gained the most population between 2000 and 2010, up about 4.3-million to more than 25-million. By percentage, Nevada was the biggest gainer in population over that period, up 35.1 perecent to 2.7-million.

By region, the South and the West accounted for the bulk of the population increase, about 14.3-million and 8.7-million, respectively. However, the Northeast and the Midwest also grew: by about 1.7-million and 2.5-million.

Puerto Rico lost 2.2 percent of its population over the past decade (the largest such decrease in the country), while Michigan lost about 0.6 percent. All other states and Washington D.C. gained population.