Louisiana lost almost 5 percent of its pre-Hurricane Katrina population during the course of the year. During the previous one-year period, the state's population had grown to 4.5 million.

Louisiana’s population totaled 4.3 million on July 1, 2006, down nearly 220,000 from one year earlier, according to estimates released by the U.S. Census Bureau. The state lost almost 5 percent of its pre-Hurricane Katrina population during the course of the year. During the previous one-year period (July 1, 2004 to July 1, 2005), Louisiana’s population had grown by 12,000, to 4.5 million.

Texas gained more people than any other state between July 1, 2005 and July 1, 2006 (579,275). Florida and California followed, gaining 321,697 and 303,402, respectively. Rounding out the top five states were Georgia (231,388) and Arizona (213,311).

Meanwhile, Arizona surpassed Nevada as the nation’s fastest-growing state over the period, with its population rising 3.6 percent. Nevada ranked second, as its population climbed by 3.5 percent, followed by Idaho (2.6 percent), Georgia (2.5 percent) and Texas (2.5 percent). The South and West again monopolized the list of fastest-growing states with Utah, North Carolina, Colorado, Florida and South Carolina rounding out the top 10. Colorado and South Carolina replaced Delaware and Oregon on the list this year.

According to the estimates, California remains the most populous state with a population of 36.5 million on July 1, 2006. Rounding out the top five states were Texas (23.5 million), New York (19.3 million), Florida (18.1 million) and Illinois (12.8 million).

Other highlights:

• North Carolina replaced New Jersey as the 10th most populous state.

• The Northeast region grew by only 62,000 people. In contrast, the South grew by 1.5 million and the West by 1 million. The Midwest added 281,000 people.

• The West was the fastest-growing region, with its population climbing by 1.5 percent. The South followed (1.4 percent), with the Midwest third (0.4 percent) and the Northeast fourth (0.1 percent).

• The South now accounts for 36 percent of the nation’s total population, with the West comprising 23 percent, the Midwest 22 percent and the Northeast 18 percent.

• The population estimate for Puerto Rico for July 1, 2006, was 3.9 million, up about 16,000 since July 1, 2005. Puerto Rico’s rate of increase was 0.4 percent.