WASHINGTON — Nine of the 10 fastest growing states from July 1991 to July 1992 were in the West, and Nevada topped the list for the second year in a row, according to the Census Bureau.

Overall, the nation’s population grew by nearly 3 million, or 1.2 percent, to 255.1 million over the year, the bureau said in a report Tuesday. A third of that growth was estimated to be immigrants.

Western states’ population increased 1.9 percent, while population rose 1.4 percent in the South, 0.8 percent in the Midwest and 0.3 percent in the Northeast.

Maine’s population grew a scant 0.1 percent from 1,234,000 to 1,235,000.

Nevada’s population rose 3.5 percent over the period, followed by Alaska, 2.9 percent; Colorado and Idaho, 2.7 percent each; Washington, 2.5 percent; Utah, 2.4 percent; Arizona, 2.2 percent; New Mexico, 2.1 percent; Hawaii, 2.0 percent; and Georgia, 1.9 percent.

In the South, only the District of Columbia lost population, declining 1.1 percent, the bureau said.

New England’s population changed little. Slight population increases in Vermont, New Hampshire, Massachusetts and Maine offset Connecticut’s decline.

The Midwest continued to recover from population losses in the 1980s.

California had the largest numerical increase, adding nearly half a million people during the period. It also accounted for nearly a third of the new immigrants.