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.
1 In 2010, women accounted for 57 percent of the population age 65 and over and for 67 percent of the population age 85 and over. 2  The United States is fairly young for a developed country, with 13 percent of its population age 65 and over in 2010.