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.
According to Age and Sex Composition: 2010 [PDF], the median age of Americans is now 37.2, with seven states recording a median age of 40 or older. The brief also shows the male population grew 9.9 percent between 2000 and 2010, while the female population grew 9.5 percent. Of the total 2010 Census population, 157.0 million people were female (50.8 percent) and 151.8 million were male (49.2 percent).