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.
U.S. population at the beginning of 2017 was over 324 million. 1 U.S. population is growing by over 2,000,000 people per year -- that's 240 per hour -- about half from new births and half from immigration. 1 According to a Global Footprint Network data, the U.S. can sustain a population of only about 150 million at a reduced consumption level similar to Europeans. 2