If present trends continue, within two decades the proportion of immigrants in the United States will surpass the peak reached more than a century ago, a new analysis concludes.

The Pew Research Center, a nonpartisan research group, estimates that sometime between 2020 and 2025, the foreign-born will account for 15 percent of the American population, or more than 1 in 7 residents. They represented about 12 percent of the population in 2005, 14.7 percent in 1910 and about 15 percent in the late 19th century.

Trends farther ahead are typically harder to predict. Still, the Pew Center projects that in 2050, 19 percent of Americans will be foreign-born; that the share of Hispanic residents will more than double to 29 percent from 14 percent in 2005; and that the proportion of Asians will almost double, from 5 percent to 9 percent.

The center estimates that the total population will grow to 438 million in 2050, with immigrants accounting for 82 percent, or 117 million, of the increase. But because births in the United States to Hispanic and Asian immigrant parents will play a progressively greater role in population growth, according to the analysis, by 2050 a smaller proportion of both groups will be foreign born in than is the case today.