While more Latinos are heading to college than ever before, that trend is not increasing uniformly throughout all U.S. colleges, according to a study released Wednesday. In fact, more than six in 10 Latino students attend a small percentage of schools with large Hispanic populations.

A majority of Latinos attended Hispanic-Serving Institutions in 2014-2015 academic year, according to a study by Excelencia in Education, an organization which has been tracking Latino college enrollment since 2004. The number of HSIs increased by 7 percent in the same year and are concentrated in 18 states.

“I think the highlight here is that Latino enrollment in higher education is increasing, but so is the concentration of Latino students on campuses,” said Deborah Santiago, chief operating officer and vice president for policy at Excelencia.

Out of all colleges and universities in the U.S., 13 percent are classified as HSI and 62 percent of Latino college students attend these schools.

To qualify as an HSI, at least 25 percent of the student body must be Hispanic or Latino. There are 435 institutions in the U.S. that fall into that category. Santiago said when you include “emerging HSIs”, which have 15-24 percent Latino enrollment rates, another 310 schools qualify.