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.
There were about 125.9 million adult women in the United States in 2014. The number of men was 119.4 million. At age 85 and older, there were almost twice as many women as men (4 million vs. 2.1 million). People under 21 years of age made up over a quarter of the U.S. population (27.1%), and people age 65 and over made up one-seventh (14.5%). The national median age was 37.8 years in 2015.