Central Illinois corn and soybean farmer Norbert Brauer said he remembers when he could plant an acre of corn for about $100 total — but that was nearly three decades ago.

A Midwest Center for Investigative Reporting analysis of the USDA data found that Monsanto has been responsible for introducing 37 different genetically engineered seeds approved by the USDA. That number is about one-third of all USDA-approved GMOs. Most of those approved seeds have been for corn, soybean and cotton.

At 76 years old, U of I graduate Mary-Dell Chilton is still working. The genetically-modified corn, soybeans and other crops that her research helped develop now grow on more than 170 million acres of U.S. farmland. Earlier this month, Chilton’s groundbreaking discoveries earned her a place in the National Inventors Hall of Fame.