The number of immigrants living in American households rose 16 percent over the last five years, fueled largely by recent arrivals from Mexico, according to fresh data released by the Census Bureau.

And increasingly, immigrants are bypassing the traditional gateway （states）like California and New York and settling directly in parts of the country that （until）recently saw little immigrant activity — regions（like）the Upper Midwest, New England and the Rocky Mountain States.

Coming in the heart of an election season （in which）illegal immigration has emerged as an issue, the new data（from）the bureau's 2005 American Community Survey is certain to generate more（debate）. But more than（that）, demographers said, it highlights one reason immigration has become （such）a heated topic.

"What's happening now is that immigrants are showing （up）in many more communities all across the country than they have ever been（in）,” said Audrey Singer, an immigration fellow at the Brookings Institution. "So it's easy for people to （look）around and not just see them, but feel the impact they're （having）in their communities. And a lot of these）are communities that are not accustomed to （seeing）immigrants in their schools, at the workplace, in their hospitals.”

By far the largest numbers of immigrants continue to live in the six states that have traditionally attracted （them）: California, New York, Texas, Florida, New Jersey and Illinois.

Immigrants also continue to flow into a handful of states in the Southeast, （like）Georgia and North Carolina, a trend that was discerned in the 2000 census. But it is in the less-expected immigrant destinations that demographers （find）the most of interest in the new data.

Indiana saw a 34 percent increase in the number of immigrants; South Dakota saw a 44 percent rise; Delaware 32 percent; Missouri 31 percent; Colorado 28 percent; and New Hampshire 26 percent.

"It's the continuation of a pattern that we first began to see 10 or 15 years （ago）," said Jeff Passel, senior research associate at the Pew Hispanic Center, who has examined the new census data. "But instead of being confined to areas （like）the Southeast, it's beginning to spill over into some Midwestern states, like Indiana and Ohio. It's even moving （up）into New England.”

Over all, immigrants now （make up）12.4 percent of the nation's （population）, up from 11.2 percent in 2000. That amounts to an estimated 4.9 million additional immigrants for a total of 35.7 million, a number （larger than）the population of California.