This table shows statistics about the US population in 2010. A table titled U S Population by age group (2010). Column 1 labeled age group: under 18, 18 to 24, 25 to 44, 45 to 64, 65 and older. Column 2 labeled percent of population: 24, 9.9, 26.6, 26.4, 13. Column 3 labeled total number: 74,181,467, 30,672,088, 82,134,554, 81,489,445, 40,267,984. Which group made up the smallest segment of the population in 2010? under the age of 18 between 18 and 24 between 25 and 44 over the age of 65