As the U.S. economy is on the mend, there is one clear trend in higher education: more students are studying science, technology, engineering and mathematics, otherwise known as STEM.

Per USA Today, College Factual has tracked the fields of studying growing fastest in popularity among students. With STEM jobs typically being more lucrative, more students are seeking degrees in that field.

But it is not just the lure of a large mid-career salary, as the STEM fields are known to be underemployed while several other career fields are competitive.

But the college major with the second largest growth is in relation to the nation's emphasis on healthcare.

1.     Behavioral Sciences

Growth: 89 percent

College Factual described this major as a "multidisciplinary study that involves the subjects of psychology, biomedical science, and sociology." The average early career salary is about $33,800, but graduates usually have their choice of several different professional fields.

2.     Health and Medical Prep Programs

Growth: 31 percent

With this degree, graduates tend to go for additional education while leaving their options open to medicine, dentistry, pharmacy and veterinary practices.

3.     Homeland Security and Emergency Preparedness

Growth: 26 percent

This is also a "multidisciplinary study" and graduates can go into a number of different career paths. Plus, the name of the major is pretty intriguing.

4.     Physical Sciences, General

Growth: 25 percent

Graduates with this degree are often best suited to be teachers, researchers or scientists. It is a field geared toward helping students understand the more broad aspects of science, rather than a concentrated program.

5.     Engineering Related Fields

Growth: 23 percent

Some jobs in engineering can be highly lucrative, but this field is typically an introduction to the field. Some schools treat Engineering Related Fields as an associate's degree, College Factual reported.

6.     Petroleum Engineering

Growth: 22 percent

While a bit more competitive and challenging than other engineering programs, Petroleum Engineering produces well paid graduates, and early in their careers.