Levene enrolled at Columbia University and in his spare time conducted biochemical research, publishing papers on the chemical structure of sugars. In 1896 he was appointed as an Associate in the Pathological Institute of the New York State Hospitals, but he had to take time off to recuperate from tuberculosis.
This graph shows the median age of the resident population of the United States from 1960 to 2015. In 2015, the median age of the United States population was approximately 37.7 years.
Today 40 million people in the United States are ages 65 and older, but this number is projected to more than double to 89 million by 2050. Rapid changes in age structure can have profound social and economic consequences. U.S. population aging has been long predicted.n 2009, the Census Bureau estimated that 55 percent of children were non-Hispanic white, compared with 80 percent of the population ages 65 and older. The share of the elderly who are non-Hispanic white is projected to drop sharply by 2050, but will still make up three-fifths of this age group (see Table 2).