Midway through the 21st century the United States population could peak at 309 million and start a gradual decline to 231 million, Census Bureau experts said.
Among other possible shifts in the population composition, the bureau calculated that there would not be as many annual births in the nation as there were during the baby boom following World War II, when births hit 4 million annually. The median age, now 30.3 years, would rise sharply to 36.3 years in the year 2000 and 41.6 years by 2050. The percentage of those 65 and older will rise from 11.4 percent last year to 21.7 percent by 2050. The ratio of the working age group to the retirement age group would fall sharply from 5.4 to 1 last year to just 2.6 to 1 by 2050.