17.3 million Americans work in the fields of science, technology, engineering and math, up from 9.7 million in 1990 — By Nikki Graf, Richard Fry and Cary Funk Employment in science, technology, engineering and math (STEM) occupations has grown 79% since 1990, from 9.7 million to 17.3 million, outpacing overall U.S. job growth. …