Every word members of Congress say on the floor of the House or Senate is documented in the Congressional Record. The Sunlight Foundation took the entire Congressional Record dating back to the 1990s and plugged it into a searchable database.

Lee Drutman, a political scientist at Sunlight, took all those speeches and ran them through an algorithm to determine the grade level of congressional discourse.

“We just kind of did it for fun, and I was kind of shocked when I plotted that data and I saw that, oh my God, there’s been a real drop-off in the last several years,” he says.