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.
Demography of the United States. The United States is estimated to have a population of 323,127,513 as of July 1, 2016, making it the third most populous country in the world. It is very urbanized, with 81% residing in cities and suburbs as of 2014 (the worldwide urban rate is 54%).