Answer: 20%
Step-by-step explanation:
Human capital refers to the expertise that people gain as a result of working. This includes skills they gain from training and actually working. For instance, the skills a Brainly website designer gets from working on Brainly.
Research suggests that this human capital has led to about a 20% growth in U.S. productivity from the year 1950 to the year 2007 which means that it is a very significant factor in the growth of the country.