According to the U.S. Census Bureau, the number of people age 90 and older in the United States grew from 720,000 in the 1980 report to 1.9 million in 2010's Census.

 By 2050 this rapidly growing segment of the population may reach 9 million, according to a report commissioned by the National Institute on Aging (NIA). The report, titled "90+ in the United States: 2006-2008," details the demographic, health and economic status of America's oldest adults and suggests that the designation of oldest-old should be changed from 85 to 90 (www.census.gov/prod/2011pubs/acs-17.pdf).

"With the aging boom it is critical to develop demographic data providing as detailed a picture as possible of our oldest population," said NIA director Richard Hodes, MD. "The information on a variety of factors-income, health status, disabilities and living arrangements-will be particularly useful to researchers, planners and policy-makers."

The 27-page report, based on the American Community Survey, notes that a majority of the 90-plus population are widowed white women who live alone or in a nursing home. Most are high school graduates. Social Security provides almost half of their personal income, and nearly all of them have health insurance coverage through Medicare and/or Medicaid. The vast majority have one or more types of disability.

According to the report, an average person who has lived to age 90 today has a life expectancy of 4.6 more years (versus 3.2 years in 1929-1931), while those who pass the century mark are projected to live another 2.3 years.

The majority (84.7 percent) of those 90 and older reported having one or more limitations in physical function. Two-thirds have difficulty in mobility-related activities such as walking or climbing stairs.

An older person's likelihood of living in a nursing home increases sharply with age. About 1 percent of the young elderly (ages 65-69) live in a nursing home. The proportion rises to 3 percent for ages 75-79, 11.2 percent for ages 85-89, 19.8 percent for ages 90-94, 31 percent for ages 95-99, and up to 38.2 percent among centenarians.

Nearly three-fourths (74.1 percent) of those age 90 and older are women. Women outnumber men almost three to one. The majority of this population are white (88.1 percent), followed by black (7.6 percent), Hispanic (4 percent), and Asian (2.2 percent).

The annual median income for this age group is $14,760. Men had a higher income than women: $20,133 vs. $13,580. Social Security represents 47.9 percent of their total personal income.

"Because of increasing numbers of older people and increases in life expectancy at older ages, the oldest segments of the older population are growing the fastest," said Richard Suzman, PhD, director of the Division of Behavioral and Social Research at NIA, which supported the report. "A key issue for this population will be whether disability rates can be reduced."