WASHINGTON - North Dakota's population boom, driven by the state's thriving oil and gas industry, continued in 2013, expanding at nearly twice the rate of the next-fastest-growing state, according to census estimates released Monday.

The West and South continued to drive population growth nationally, accounting for more than four in five new residents, while growth in the Northeast and Midwest continued to lag.

Population estimates are eagerly watched by state officials, since they determine the flow of money into many federal programs, and, ultimately, representation in Congress. The number of representatives each state has in the House gets readjusted each decade.

California (38,332,521) and Texas (26,448,193) remain the nation's most populous states, with New York (19,651,127) narrowly maintaining its third position over Florida (19,552,860) as of July 1. The Sunshine State will soon surpass New York, if it hasn't already, because its population grew three times faster, according to the census estimates, which are based on data measuring births, deaths, and migration.

California's population growth again outpaced the national trend, with an increase of 332,643, or 0.9 percent. Texas actually saw a greater raw population increase, however, expanding by 387,397.

North Dakota's population stood at 723,393 on July 1, according to the census data, a 3.1 percent increase from 2012. Since the 2010 census, North Dakota's population has grown 7.6 percent, far outpacing the national growth rate of 2.4 percent during that period.

Population in the District of Columbia also grew at a sustained clip, rising 2.1 percent year to year to 646,449. Utah grew next fastest, at a rate of 1.6 percent, followed by Colorado (1.5 percent), Texas (1.5 percent) and Nevada (1.3 percent).

West Virginia and Maine saw slight population declines in the last year. Pennsylvania, New Mexico, Vermont and Illinois posted the slowest population growth, all at or near a tenth of a percentage point year to year.

The national population stood at 316,128,839 on July 1, an increase of 2.3 million, or 0.7 percent from the previous year.