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.
The most common age in America is now 22, according to the New York Times. Just as recently as 2010, the most common age was 50. Now, the tides have changed. In second and third place are 21 and 23-year-olds, with 53-year-olds in fourth place. For those that question the logic of growth, it's partly due to immigration, the report said. One might think that the size of any age cohort could only decline as it ages. Some people now 19 will die within the next year, and no new 20-year-olds will be born. But because of immigration, the Census Bureau says, most age groups up to about 40 years old are getting larger every year. As a result, the groups in their 20s are growing, while those of baby boom age are declining in size..