Data from the 2000 U.S. Census, which is being released by the government gradually over time, is beginning to build a demographic snapshot of the country's immigrant population. There are more than 30 million foreign-born residents of the United States and 44 percent of them arrived in the ten years since the 1990 census.

Eighty percent of the new arrivals are from either Asia or Latin America. The U.S. Asia-born population alone grew from one million to 12 million over the last three decades.

Immigrants are predominant at both ends of the educational spectrum. A higher percentage have more education than the average, native born American and a higher proportion have less education.

Once concentrated primarily in large cities, U.S. immigrants have spread out across the country over the last ten years. Twenty-seven of the 50 states have populations that are at least five percent foreign born.

States with the highest concentrations of immigrants have the greatest economic growth. Is that because immigrants contribute to economic growth or because they are attracted to fast growing areas? Urban Institute demographer Jeffrey Passell says the question is a difficult one to answer. "My own sense is it's a mixture," Mr. Passell said. "The immigrants tend to be drawn to places with vibrant economic opportunities. In addition to that, the presence of immigrants and the entrepreneurial activities associated with new immigrants has tended to revitalize neighborhoods."

Some of the Census numbers lead to multiple interpretations. Americans were shocked, for example, by a report that 20 percent of all immigrant homes do not speak English.

Demographer Guillermina Jarro says a closer look at the data reveals that 20 percent of immigrant homes do not speak only English. "The census asks: 'Does this person speak a language other than English at home?' So what you are able to do with that data is classify it into two groups: The group that speaks only English at home, and everybody else. Now that 'everybody else' includes people who also speak English at home but who do not only speak English at home. They also speak another language," she explained.

Demographer Jeffrey Passell says the data released so far has made him impatient for more. "It would be wonderful to have information on the employment characteristics of immigrants where they are working, what their incomes are, particularly broken down by country and by year of entry so we could begin to look at the progress of immigrants over time," he said.

That will come later, Mr. Passell says, as more and more details of the 2000 census are tallied and released to the public.