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.
Below are the key figures for United States of America (USA) population in 2016: 1  4,070,119 live births. 2  2,661,729 deaths. 3  Natural increase: 1,408,390 people. 4  Net migration: 1,023,990 people. 5  160,669,833 males as of 31 December 2016. 6  164,787,883 females as of 31 December 2016.