WASHINGTON (Reuters) — One hundred years from now, the United States will be twice as populated but will look more diverse, the government said on Thursday. According to computer-generated projections at the Census Bureau, which is charged with enumerating the nation's resident population, there will be 571 million residents in 2100, more than double the estimated 273 million in 1999. ``The increasing number of potential parents and continued migration from abroad would be sufficient to add nearly 300 million people during the next century,'' Frederick Hollmann, demographer at the bureau's population projection branch, said.

As the population of the United States — which in the projections include only the 50 states and the District of Columbia — changes, so does the country's ethnic proportions as the white majority begins to fade, and Hispanics and Asians take on bigger roles in U.S. demographics. The Census projected that in 2059 non-Hispanic whites will make up less than 50 percent of the total population.

A Surge in Hispanics and Baby Boomers

The Census said it believes that by 2005 Hispanics may become the nation's largest minority group, surpassing blacks. The transition may happen between 2004 and 2005 when the Hispanic population may match the black population at 13 percent of the total population.

The Hispanic population is projected to nearly triple by 2050 to 92 million, or 24 percent of the total population. The Census estimates that 12 percent of the U.S. resident population in last year were Hispanic, equivalent to 31 million. In the following 50 years, the group is projected to hit 190 million, or one-third of the population.

The Census also projects the number of Asians and Pacific Islanders will more than triple in 50 years to 38 million, or 9 percent of the total count, from an estimated 11 million, or 4 percent, in 1999. By 2100, they are projected to reached 75 million, or 13 percent.

'The Hispanic and Asian populations grow faster due to birth rates and net migration,' said demographer Tammany Mulder. `Hispanics generally have higher fertility rates and Asians have high net migration rates to the U.S.'

For example, a Hispanic woman of child-bearing age had an estimated 2.9 babies in 1999, compared with 1.8 babies for a non-Hispanic white woman, and 2.1 for a black woman. By 2050, the fertility rate for a Hispanic woman is projected to increase to an average 2.7 babies, compared with 2.0 babies for a non-Hispanic white woman and 2.1 babies for a black woman.

The projections also show a rapid surge in the elderly population as the surviving baby boomers, those born between 1946 and 1964, pass age 65. Between 2011 and 2030, the proportion of the elderly to the rest of the country is expected to surge to 20 percent from 13 percent, a gain of almost 30 million baby boomers entering retirement age.

The projections also show more women than men in the next century. A higher percentage of the elderly are expected to be women, who generally live longer than men.

First Projection to 2100

``We have produced projections before with long time spans,'' Mulder said. ``This is the first time we've gone out to 2100. We recognize the uncertainty of the projections.''

The study was based on demographic research on birth rates, death and migration to the United States. Events such as war, advances in medicine and technology that may help increase life expectancy and random natural occurrences, such as diseases and floods, were used to project the count. The first census which was taken in 1790 counted 3.9 million Americans.