WASHINGTON — Nearly 1 in 5 people living in the United States speak a language at home other than English, according to new Census data that illustrate the wide-ranging effects of immigration.

In South Carolina, about 5 percent of the population speaks a language other than English at home, although that isn't necessarily Spanish. The number of immigrants of Hispanic or Latino origin in the state was 141,721 in 2006, up 7,846 from 2005.

Nationwide, the number of immigrants reached an all-time high of 37.5 million in 2006, affecting incomes and education levels in many cities across the country. But the effects have not been uniform.

In most states, immigrants have added to the number of those lacking a high school diploma, with almost half of those from Latin America falling into that category.

However, at the other end of the education spectrum, Asian immigrants are raising average education levels in many states, with nearly half of them holding at least a bachelor's degree.

"There is no one-size-fits-all policy that you could apply for all immigrant groups," said Mark Mather of the Population Reference Bureau. "I think most of the attention has been on low-skilled workers coming from Mexico. But we have 10 million immigrants from Asia, a number that's growing."

The Census Bureau today released a host of demographic data about the nation, including statistics on immigration, housing, education and employment.

The data come from the American Community Survey, an annual survey of 3 million households that has replaced the Census Bureau's long-form questionnaire from the once-a-decade census. It does not distinguish between legal and illegal immigrants.

Mather analyzed the differences in education levels among immigrants from Asia and those from Latin America. Together, the groups account for about 80 percent of all immigrants.

About 48 percent of Asian immigrants held at least a bachelor's degree, compared with about 11 percent of immigrants from Latin America. Among people born in the United States, about 27 percent were college graduates.

"Driving this are people coming from China and India," Mather said. "They are either coming with a bachelor's degree or they are coming with visas and getting degrees once they arrive."

At the other end of the spectrum, 47 percent of adult immigrants from Latin America lacked a high school diploma, compared with 16 percent of Asian immigrants and 13 percent of people born in the United States.

Those numbers are fueling overall increases in the number of high school dropouts in four states: Nevada, Arizona, Colorado and Texas, said William Frey, a demographer at the Brookings Institution, a Washington think tank.

"It used to be the poor Southern states that had low levels of education and income. Now it is the high-immigration states as well," Frey said. "But that isn't to say that the second or third generation won't do better, because they will," he added. "There is upward mobility."

Among the other highlights from the 2006 data released by the Census Bureau:

--Massachusetts led all states in college graduates, with 37 percent of adults 25 and older holding at least a bachelor's degree. West Virginia was last with 16.5 percent.

--Mississippi led all states in high school dropouts, with 22.1 percent of adults 25 and older not graduating from high school. Minnesota was at the other end, with only 9.3 percent.

--California led the nation in immigrants, at 27 percent of the state's population, and in people who spoke a foreign language at home, at 43 percent.

--West Virginia had the smallest share of immigrants, at 1.2 percent. It also had the smallest share of people speaking a foreign language at home, at 2.3 percent.

--New York residents had the longest average commuting time to work, at nearly 31 minutes, while North Dakota had the shortest, at 15.5 minutes.

--More Americans are working later in life. In 2006, 23.2 percent of people age 65 to 74 were still in the labor force, either working or looking for work, up from 19.6 percent in 2000.

--Fewer households consist of a married couple with children, 21.6 percent in 2006, down from 23.5 percent in 2000.